Patent Abstract:
A service device connects to a service port of a pressurized system. The device includes a valve opening member for opening a valve within the port. The device can attach to a service unit for servicing the pressurized system. The system can be an air conditioning or refrigeration system.

Full Description:
CLAIM OF PRIORITY 
   This application is a utility filing of the provisional application U.S. patent application Ser. No. 60/343,181 filed on Dec. 31, 2001, the entire contents of which are hereby incorporated by reference. 

   TECHNICAL FIELD 
   This invention relates to a coupling for servicing a pressurized system. 
   BACKGROUND 
   Servicing couplings are commonly employed to facilitate charging and evacuation of pressurized fluid systems, such as refrigeration systems, air conditioning systems, or hydraulic systems. The service coupling connects to a service port of the system. The service coupling opens a service port of a system, allowing fluids, including liquids or gases, to be exchanged with the system. A quick-release interconnection between the service port and the service adapter can facilitate the servicing process. For example, when servicing a refrigeration or air conditioning system the service coupling can be connected by a flexible hose to a refrigerant supply source, such as a pressurized bottle or cylinder. When the service coupling and service port is opened, refrigerant can flow through the coupling and into the refrigeration system. Because pressurized fluid systems can be serviced when the system is installed in a confined space such as a vehicle, service couplings having small dimensions can be useful for convenient servicing. 
   SUMMARY 
   In one aspect, a service device includes a body having a first end engagable with a service port, a second end engagable with a service unit, and an inner surface defining an interior chamber. The device includes a valve opening member disposed in the interior chamber, and a service port opening member configured to rotate the valve opening member relative to the body, the first end and the second end being in fluid communication when a service port is engaged with the first end and the service port is opened. 
   The valve opening member can include a plug engaging end proximate to the first end, the plug engaging end being capable of changing position relative to the first end. 
   The device can also include a spring within the body, biasing the valve opening member toward the first end, and a sealing gasket between the body and the first end. The first end can be capable of forming a seal with the port when the first end is engaged with the service port. The plug engaging end can have a cross section having a substantially hexagonal shape. The body can be a portion of a coupling device. The first end can be engagable with a refrigerant port. 
   The device can include a valve member within the body having a first position oriented closer to the first end relative to a second position, the valve member moving from the first position to the second position when the service port is engaged with the first end of the body and the service port is opened. The first end can be in fluid communication with the second end when the valve member is in the second position. The valve member can be slideably disposed on a surface of the service port opening member. 
   The device can be a coupling member. An air conditioning or refrigeration service device can include a service unit including the coupling member. 
   In another aspect, a method of opening a service port includes adjusting a position of a valve opening member relative to a first end of a service port connector, and opening a valve within the service port. The valve opening member can include a plug engaging end proximate to the first end. The service port connector can be attached to a service unit or can be capable of attaching to a service unit and the first end can be engagable with the service port. The valve opening member can rotate relative to the body to open the valve. Adjusting can take place upon attaching the service port connector to the service port. The method can also include sealing the connector to the port prior to opening the valve. Opening the valve can actuate a valve member within the connector to bring a first end of the connector and a second end of the connector into fluid communication. 
   The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 

   
     DESCRIPTION OF DRAWINGS 
       FIG. 1A  is a sectional view of a service coupling. 
       FIG. 1B  is a sectional view of an engagement member of the service coupling along the line  1 B— 1 B of FIG.  1 A. 
       FIG. 2  is a sectional view of a service port. 
       FIG. 3  is a sectional view of the service coupling connecting to a service port. 
       FIG. 4  is a sectional view of the service coupling connected to the service port. 
       FIG. 5  is a sectional view of the service coupling opening the service port. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1A , a service coupling  100  includes a mating portion  110  for coupling to a service port, a port  120 , and a flow path control portion  130  that allows an operator to control a fluid flow path between mating portion  110  and port  120 . 
   Port  120  can be attached to service equipment to connect the equipment to the service port. For example, the service port can be a service port of an automotive air conditioning system and the service equipment can include any sort of maintenance or repair system, such as a diagnostic tester, fluorescent leak detection system (i.e., dyes, injection system, lights), electronic leak detection system, recovery and recycling machine radiator service device, refrigerant identification tester, a flushing system, an oil insertion system, or a manifold gauge set. 
   Service coupling  100  is formed by a main body member  140 , a flow path control portion  130 , a knob  260 , and a port nozzle  125 . 
   Main body member  140  is generally tubular in shape and has an outer surface  148 , an inner surface  146 , a first end  141 , and a second end  149  opposite first end  141 . End  141  of main body member  140  defines hole  144  dimensioned to receive ball bearing  320 . Ball bearing  320  is retained in hole  144  by an annular ring  310  which surrounds a portion of outer surface  148 . Ball bearing  320  is arranged to engage a service port when inserted into mating portion  110 . 
   Annular ring  310  includes an inner face  313  with an interior annular lip  314  having a raised portion  315 . Interior annular lip  314  has a lip wall  12 . Inner face  313  and outer surface  148  of main body member  140 , along with lip wall  12  and a lateral wall  143  on outer surface  148  of main body member  140 , together define an annular volume  340  which houses a spring  330 . Spring  330  biases lip wall  12  away from lateral wall  143  so that annular ring  310  contacts retaining ring  302  and is compressible toward lateral wall  143  to allow ball bearings  320  to project into notch  301  from channels  144  thereby releasing a service port received in mating portion  110 . 
   Inner surface  146  at end  141  of main body member  140  defines a chamber  410  for receiving a service port into mating portion  110 . Inner surface  146  also defines an annular groove  147  around chamber  410  for receiving a sealing member  184  which seals to a service port when received in mating portion  110 . In addition to inner surface  146 , chamber  410  is bounded by a central body member  220  and a valve member  170 . 
   Central body member  220  is also generally tubular in shape and has an outer surface  228 , an inner surface  226 , a first end  221 , and a second end  229  opposite first end  221 . Central body member  220  defines a volume  230  and channels  231 ,  232  that communicate between outer surface  228  and inner surface  226 . Central body member  220  also includes a lateral wall  225  that extends inner surface  226  into axial volume  230 . Orifice  233  located at end  229  extends from volume  230  to outer surface  228 . 
   Axial volume  230  contains an elongate engagement member  150  that extends into chamber  410 . Engagement member  150  has a first end  151 , a second end  159  opposite first end  151 , and a wall  156  including a pair of opposing lateral slots  154  (only one is shown) and an axial channel  155  extending from first end  151  to second end  159 . Lateral slots  154  have a first end  152  and a second end  158 . Pin  160  is contained between first end  152  and second end  158  in slots  154 , and traverses laterally through engagement member  150 . Pin  160  is mechanically joined to central body member  220 . Engagement member  150  is slidable along pin  160 , allowing relative axial movement between member  220  and engagement member  150  over the span between first end  152  and second end  158 . Pin  160  can also transmit torque from handle  260 , through member  220  to engagement member  150 . Spring  190  is contained in axial volume  230  between lateral wall  225  of central body member  220  and end  159  of engagement member  150 , biasing engagement member  150  toward mating portion  110 . Spring  190  allows engagement member  150  to be driven into axial volume  230  during insertion of a service port into chamber  410  if engagement member  150  is not aligned properly with the service port, as discussed further below in regard to FIG.  2 . 
   Annular valve member  170  is also generally tubular in shape and has an outer surface  178 , an inner surface  176 , a first end  171 , and a second end  179  opposite first end  171 . Inner surface  176  defines an annular groove  17  for receiving a sealing member  250  to seal valve member  170  to outer surface  228  of central member  220 . Annular valve member  170  defines channels  174  which span between outer surface  178  and inner surface  176 . Fixed seal  240  is attached to surface  146  and forms a releasable seal between surface  146  and surface  178 . Annular valve member  170  also includes an outwardly extending lip  177  contacting a spring  180  circumscribing outer surface  178  of annular valve member  170  and outer surface  228  of central member  220  but within inner surface  146  of main body member  140 . Spring  180  biases annular valve member  170  to form the seal between surface  178  and surface  146 . Annular valve member  170  is slidable along outer surface  228  of central member  220 . When member  170  slides away from the mating region  110 , for example, when coupled to a service port as described below, the releasable seal formed between fixed seal  240  and inner surface  146  to form a fluid flow path from chamber  410  through channels  174  to channel  126  of port nozzle  125 , which, in turn, is in fluid communication with orifice  127  of port nozzle  125 . 
   Flow path control portion  130  includes knob  260 , which as describe above, applies torque to engagement member  150  by rotating inner knob  280 . Inner knob  280  is fixed to central body member  220 . Outer ratchet teeth  264  of knob  260  contact and mate with inner ratchet teeth  224  of inner knob  280 . Gasket  200  is located between knob  260  and knob  280  over orifice  233 . Gasket  200  is secured to knob  260  by fastener  210  and fastener  212 . Spring  291 , which is located between inner knob  260  and holding plate  290 , biases knob  260  toward mating portion  110 . This bias holds ratchet teeth  264  in contact with ratchet teeth  224 . Biasing of knob  260  toward mating portion  110  by spring  291  also forms a seal between gasket  200  and orifice  233 . 
   When knob  260  is rotated in a direction that opens an engaged service port (for example, a counter-clockwise direction when knob  260  is viewed from above), a surface of ratchet teeth  264  presses against a surface of ratchet teeth  224  in an orientation parallel to the axis of rotation. This configuration allows all torque applied to knob  260  to be applied to member  150  when opening the service port because no slipping occurs between knob  260  and inner knob  280 . When knob  260  is rotated in a direction that closes an engaged service port (for example, a clockwise direction when knob  260  is viewed from above), a surface of ratchet teeth  264  presses against a surface of ratchet teeth  224  in an orientation that is not parallel to the axis of rotation. This configuration allows slippage to occur when the torque applied to knob  260  overcomes friction between the surface of ratchet teeth  264  and ratchet teeth  224  when closing the service port, thereby avoiding application of a potentially damaging force to the service port. The friction can be influenced by spring  291 . When slippage occurs, knob  260  moves away from member  220 , allowing the seal between gasket  200  and orifice  233  to break during the slippage. 
   Referring to  FIG. 1B , wall  156  of engagement member  150  forms a hexagonal cross-section circumscribing axial channel  155  for engaging and rotating a service port received in mating portion  110 . 
   Referring to  FIG. 2 , a service port  500  includes a body  550  and a plug  600 . Body  550  includes a conduit portion  558  for conducting fluid and a mating portion  552  for connecting to service coupling  100 . Conduit portion  558  includes a wall  556  defining a fluid channel  560 . Mating portion  552  is generally tubular and has an end  559 , an outer surface  557 , and an inner surface  556 . Mating portion  552  is joined to conduit portion  558 . Outer surface  557  can form a seal with sealing member  184  of coupling  100 , as discussed further below. Inner surface  556  defines a chamber  510  and includes a threaded portion  554 . When port  500  is assembled, chamber  510  receives plug  600 . Plug  600  is generally tubular in shape and includes a wall  620  with a first end  621 , a second end  629 , an outer surface  628 , and an inner surface  626 . End  621  of plug  600  is capped by a conical tip portion  610 . Tip portion  610  includes an outer sloped surface  604  extending away from end  621 . Outer surface  628  of wall  620  has a thread  624  are dimensioned to threadedly mate with threaded portion  554  of inner surface  556  of body  550 . End  621  includes orifice  630  penetrating wall plug  600 . In a closed position (as shown), tip portion  610  extends into fluid channel  560  and sloped surface  604  of tip portion  610  seals with wall  556  of fluid channel  560  at contact region  700 . Inner surface  626  defines cavity  611 , which can be hexagonal in cross-section and dimensioned to snugly receive engagement member  150  so that rotation of engagement member  150  can impart a rotational force to sealing member  600  and move sealing member  600  along threads  555  to open and close service port  500 . In the closed position, radial seal  700  prevents fluid communication between fluid channel  560  and chamber  510 . In an open position (not shown), contact in region  700  is broken bringing chamber  510  and channel  560  into fluid communication through orifice  630 . 
   Referring to  FIG. 3 , in use, an operator inserts end  559  of service port  500  into mating portion  110  and chamber  410  of service coupling  100 . Sealing member  184  seals outer surface  557  of service port  500  to inner surface  146  of main body member  140 . Ball  320  engages with outer surface  557 , holding port  500  in coupling  100 . Cavity  611  is dimensioned to receive engagement member  150 , each of which can have a hexagonal cross section. However, at the time of insertion, the cavity  611  of plug  600  may not be properly oriented to receive engagement member  150 , in which case end  151  of engagement member  150  catches on end  629  of plug  600 . As a result, end  629  forces engagement member  150  into volume  230 , compressing spring  190 . Slots  154  accommodate the inward movement of engagement member  150  as member  150  slides along pin  160  from first end  152  to second end  158 . The movement of member  150  allows coupling  100  to mate with port  500  without damaging the coupling or the port. 
   Referring to  FIG. 4 , with service port  500  in chamber  410  of service coupling  100 , the operator manually commences rotating knob  260 . Knob  260  is mechanically joined to pin  160 , which also commences rotation about axis A. The rotation of pin  160  in turn rotates engagement member  150  to align the cross-sectional pattern of member  150  with the cross-sectional pattern of cavity  611 . When the cross-sectional patter of member  150  is aligned with the cross-sectional pattern of cavity  611 , spring  190  slides member  150  along slot  154  and pin  160  and into cavity  611  to engage plug  600 , thereby coupling plug  600  and knob  260  for combined rotation. 
   Referring to  FIG. 5 , once member  150  is engaged with plug  600 , as described above, rotation of plug  600  using knob  260  moves plug  600  along threads  555  of service port body  550 , separating sloped surface  604  from wall  556  and opening service port  500 . As plug  600  is rotated, engagement member  150  extends progressively deeper into cavity  611  and tip  610  progressively withdraws from fluid channel  560  to place fluid channel  560  in communication with the fluid path formed by channel  155  and volume  230 . As plug  600  moves along member  150 , end  629  of plug  600  contacts end  171  of valve member  170  and slides valve member  170  toward knob  260  along central member  220 . As member  170  slides toward knob  260 , the seal between surface  178  and surface  146  at fixed seal  240  breaks, allowing volume  230  and channel  126  to fluidly communicate via channels  231 ,  232 . Valve member  170  detects the presence plug  600  and the opening of the service port and moves toward knob  260  to form an uninterrupted fluid flow path from fluid channel  560 , through channel  155  and volume  230  to channel  126  in port nozzle  125 . With this arrangement, the operator will not be able to break the seal at a fixed seal  240  until service port  500  is received in chamber  410  of service coupling  100  and service port  500  has been broken when the port is opened. As described above, when knob  260  is rotated in a direction that closes an engaged service port, a surface of ratchet teeth  264  presses against a surface of ratchet teeth  224  in an orientation that is not parallel to the axis of rotation, allowing slippage to occur and causing the seal between gasket  200  and orifice  233  to break during the slippage. The slippage occurs when plug  600  has been rotated to the closed position. The breaking of the seal between gasket  200  and orifice  233  that occurs once plug  600  has been rotated to the closed position allows pressure within the coupling to be equalized with the ambient environment. 
   A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Technology Classification (CPC): 8