Patent Abstract:
A system and method for exchanging used hydraulic fluid with fresh hydraulic fluid in an accessed hydraulic fluid system. The system includes a fluid exchange assembly, a flow-aligning valve assembly and a locking mechanism. The locking mechanism allows the pressure of the fresh fluid being conducted to the hydraulic fluid system to be increased by a boost pump beyond the nominal pressure of the used fluid being conducted from the fluid system to the valve assembly during an exchange procedure. Together the boost pump and locking mechanism provide for an efficient exchange of fluids within a hydraulic system, particularly those hydraulic systems exhibiting relatively low flow.

Full Description:
RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/850,149, filed Oct. 5, 2006. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to hydraulic fluid exchanging devices, and more particularly to an apparatus for achieving and maintaining proper fluid flow alignment between a fluid exchange device and an accessed hydraulic fluid system, particularly those fluid systems having low flow, such as certain types of vehicular automatic transmissions.  
       BACKGROUND OF THE INVENTION  
       [0003]     The market for fluid exchanging equipment for vehicular hydraulic fluid systems, such as power steering and automatic transmissions, has undergone relatively rapid expansion. Many such devices have been recently developed. One unresolved problem has been the inherent need for an inexpensive fluid exchange system which is simple to operate and which supports desirable features of some known, more complex and expensive exchange units, such as an automatic bypass mechanism and such as the automatic fluid flow alignment mechanism as disclosed in U.S. Pat. No. 5,472,064 and U.S. Pat. No. 6,330,934 and U.S. Pat. No. 6,779,633 to Viken, each patent being incorporated by reference herein.  
         [0004]     An unresolved need remains for a fluid exchanger capable of servicing automatic transmissions having low fluid flow such as certain Ford Explorers, Ford pick-up type trucks, and other Ford vehicles, and some Geo Metros and other small foreign designed vehicles, and certain Toyotas and the like.  
         [0005]     A need remains for simple and inexpensive fluid exchanger which can be interconnected to a low flow hydraulic circuit, such as that of a vehicular automatic transmission, and which has features of automatic fluid flow alignment, automatic bypass established at the completion of the fluid exchange, and which has the ability to apply low pressure to the fluid being discharged from the accessed hydraulic circuit while pumping the fresh fluid into that hydraulic circuit. Such a device would need to accomplish these objects without disrupting the normal fluid flow patterns of the accessed hydraulic circuit while preferably maintaining equalized flow rates between the used fluid being discharged from the hydraulic circuit and the fresh fluid being pumped into that circuit.  
       SUMMARY OF THE INVENTION  
       [0006]     A fluid exchange device in accordance to the present invention includes a multi-port valve assembly and a lock component. The valve assembly is in fluid communication with an accessed hydraulic system via a pair of flexible conduits. The valve assembly controls directions of fluid flow within the device during an exchange procedure. A boost pump may be utilized to increase a flow of fluid through the exchange device. In one embodiment, the lock component restrains a portion of the valve assembly during the exchange procedure in order to maintain proper fluid flow while the boost pump is activated.  
         [0007]     Addressing the deficiencies of the conventional art, a fluid exchange device of the present invention resolves unmet needs in an efficient, cost effective manner. The fluid exchange device is relatively easy to operate and adaptable to a variety of automatic transmissions or hydraulic circulating systems and the like of vehicles, machinery, aircraft and equipment. In one embodiment, a fluid exchange device in accordance with the present invention includes a locking mechanism connected to an automatic flow-aligning valve assembly which allows a boost pump to be operated. A bypass device for removing a portion of the exchange device from the accessed hydraulic circuit at the completion of the fluid exchange is also provided. The fluid exchange system of the present invention can be utilized while the accessed hydraulic circuit is operational and without any change in the fluid volume contained in the accessed hydraulic system. The locking mechanism allows the fluid exchange system to include a boost pump to either the used fluid conduit on the fresh fluid conduit or both without disrupting the operation of the automatic fluid alignment assembly which is controlled at the onset by the fluid pressure provided by the accessed hydraulic system alone. As such, the fluid pressure of the accessed hydraulic system determines the fluid alignment of the fluid exchange device at the start of the exchange procedure after which the locking mechanism is activated to maintain fluid flow alignment after the boost pump is activated.  
         [0008]     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a schematic view of a fluid exchange system according to the present invention  
         [0010]      FIG. 2  is a schematic view of the automatic fluid-aligning valve assembly and the locking mechanism of  FIG. 1 .  
         [0011]      FIG. 3  is an exploded view of the integral parts of the automatic flow alignment structure and locking mechanism of  FIGS. 1, 2 ,  4  and  5 .  
         [0012]      FIG. 4  is a schematic view of the automatic fluid alignment structure and its attached locking mechanism of  FIG. 2  and shows the automatic fluid alignment structure in its initial unlocked condition as proper fluid flow alignment in the process of being attained.  
         [0013]      FIG. 5  is a schematic view of the automatic fluid alignment structure with locking mechanism operating in a properly aligned and locked condition, thus maintaining proper flow alignment while the fluid pump arranged to its used fluid conduit is operated to assist the exchange of fluids of a low flow hydraulic circuit or to speed up the fluid exchange.  
         [0014]      FIG. 6  is a schematic view of an alternative embodiment of an automatic fluid-alignment valve assembly with more than one locking mechanism operating in a properly aligned and locked condition. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     Referring now to the drawings, where like numerals represent like parts throughout,  FIG. 1  is a schematic view of fluid exchange system  10  having an automatic flow-aligning valve assembly  2  and locking mechanism  1 . A fluid exchanger, in this embodiment, diaphragm tank  3 , is utilized during an exchange procedure to receive used fluid from an accessed hydraulic system and provide fresh fluid to the hydraulic system. Diaphragm tank  3  provides for a substantially equivalent exchange rate, i.e., the flow rate of used fluid extracted from the hydraulic system is about the same as the flow rate of new fluid introduced into the hydraulic system. Additional features of diaphragm tank  3  as well as alternative fluid exchangers are found in applicant&#39;s U.S. Pat. Nos. 5,318,080, 6,082,416, 6,164,346, 6,223,790, 5,267,160, 6,378,657, 6,446,682, 6,779,633, 6,962,175, each being incorporated by reference herein. As a result, a variety of different fluid exchanger may be utilized with flow-aligning valve assembly  2  and locking mechanism  1  in accordance with the present invention. For example, a moveable piston with seals inside a fixed volume cylinder, with the piston separating variable volume but reciprocally interdependent fresh and used fluid chambers is another type of used fluid and fresh fluid flow balancing structure that can be substituted for diaphragm tank assembly  3 .  
         [0016]     Fluid exchange system  10  includes a pair of fluid exchange conduits  15 ,  17  which are respectively connected at one end to quick connect  21  and quick connect  19 , and at the other end to port  50  and port  52  of the automatic flow-aligning valve assembly  2 .  
         [0017]     Prior to the exchange procedure, quick connect  19  and quick connect  21  are selectively connected to an opened fluid circulation circuit of the hydraulic system. A fluid exchange system may be accessed by way of adapters connected to the opened fluid circulation circuit. For example, the cooling circuits of a variety of different automatic transmissions may be accessed with quick connects  19 ,  21  and an adapter kit (not shown, but well understood in the art).  
         [0018]     Automatic flow-aligning valve assembly  2  is operatively connected to locking mechanism  1 . Locking mechanism  1  has solenoid coil  6  that is energized by 120 volts AC electrical current supplied by relay  9 . An AC plug  13  has ground wire  38  that is connected to relay  9  and to ground wire  36  that is in turn connected to boost pump  5  at one of a set of leads  83 . Automatic flow-aligning valve assembly  2  has hex plug  63  and hex plug  69  which seals and blocks, at either end, valve bore  178  (shown in  FIGS. 2, 3 ,  4  and  5 ). Locking mechanism  1  may include other mechanical and/or electro-mechanical devices operatively connected to flow-aligning valve assembly  2  in order to lock a component or assembly within flow-aligning valve assembly  2  in a selected position during a fluid exchange procedure.  
         [0019]     Locking mechanism  1  is fresh fluid controlled and allows the automatic flow-aligning valve assembly to be interconnected into the two fluid exchange hoses at any point, even close to the ends of the hoses where they are connected to the opened hydraulic circuit being serviced. This allows automatic flow-aligning valve assembly  2  and locking mechanism  1  to be sold as an aftermarket item to be easily retrofitted to any fluid exchanger which does not have an integral automatic flow alignment valve and which has a pair of fluid exchange hoses with one being a used fluid discharge hose and the other being a fresh fluid delivery hose.  
         [0020]     Locking mechanism  1  has an operator rod containment assembly  4 , which contains an internal operator rod assembly  166  (shown in  FIGS. 2, 3 ,  4  and  5 ). Operator rod containment assembly  4  has balance port  28  to which check valve  86  is connected, which in turn is connected to used fluid conduit  23 . Used fluid conduit  23  is connected at another one of its ends to used fluid outlet port  58  of automatic flow alignment valve  2 , connected at another one of its ends to check valve  37 , and connected at another of its ends to pump head  18 .  
         [0021]     Locking mechanism  1  is electrically operated. Referring to  FIG. 1 , hot wire  48  is connected at one end to relay  9  and at the other end to an on-off toggle switch  11 . Neutral wire  51  is connected at one end to relay  9  and at the other end to toggle switch  11 . Hot wire  42  is connected at one end to AC plug  13  and at its other end to on-off toggle switch  11 . Hot wire  46  is connected at one end to one of the set of leads  83  of boost pump  5 , at another end to relay  9 , and also to hot wire  22 . Neutral wire  40  is connected at one end to AC plug  13  and at its other end to on-off toggle switch  11 . Hot wire  22  is connected to one of a pair of leads  69  of solenoid coil  6  at one end and at its other end to hot wire  46  that is connected at one end to relay  9  and at another end to one of a set of leads  83  of boost pump  5 . Hot wire  24  is connected at one end to one of the pair of leads  69  of solenoid coil  6  and at its other end to neutral wire  39  which is connected at one end to one of the set of leads  83  of boost pump  5  and at its other end to relay  9 . Signal wire  44  is connected at one end to one of a pair of leads  81  of flow switch  7  and at its other end to relay  9 . Signal wire  47  is connected at one end to one of the pair of leads  81  of flow switch  7  and at its other end to relay  9 .  
         [0022]     Boost pump  5  in this embodiment is vane pump having pump head  18 , which is powered by pump motor  16  at 120 volts AC. Pump motor  16  is connected to pump head  18  by pump coupler assembly  20 . Pump head  18  contains a set of rotating vanes (not shown but understood in the art). Of course many other types of pumps can be substituted and would work equivalently. In this preferred embodiment boost pump  5  is a rotary vane pump, such as manufactured by Tuthill Corporation, Pump Model No. P11347 and disclosed in U.S. Patent Pub. No. 2005/0214153 to Citro et al., incorporated by reference herein.  
         [0023]     Used fluid conduit  23  connects used fluid outlet port  58  of automatic flow-aligning valve assembly  2  with check valve  37 , with pump head  18 , and with check valve  86  which is connected to balance port  28  of operator rod containment assembly  4  within locking mechanism  1 . Operator rod containment assembly  4  contains an operator rod assembly  166  (as shown in FIGS.  2 , 3 , 4 , 5 ). Fresh fluid conduit  25  connects fresh fluid inlet port  54  and fresh fluid inlet port  56  to flow switch  7 .  
         [0024]     Fresh fluid conduit  29  connects fresh fluid fill port quick connect  30  to bypass valve  35  at port  94  and to flow switch  7 . Bypass valve  35  has male threads at its base (not shown) and is sealably connected with a nitrile type O-ring type seal to an opening at a top female threaded orifice (not shown) of top tank half  59  of diaphragm tank assembly  3  which also has bottom tank half  62 .  
         [0025]     Used fluid conduit  26  connects pump head  18  to check valve  37 , to used fluid port  31  of bottom tank half  62 , to bypass check valve  34 , and to used fluid discharge port quick connect  32 . Bypass conduit  27  is connected at one end to bypass check valve  34  and at its other end to bypass valve  35 .  
         [0026]     Diaphragm tank assembly  3  is comprised of displaceable diaphragm  8  enclosed inside top tank half  59  and bottom tank half  62 , and secured to be fluid tight by a set of 24 identical fastener assemblies of which a connecting bolt/washer/nut assembly  12  and a connecting bolt/washer/nut assemblies  14  comprise two of the 24 identical fastener assemblies.  
         [0027]     Bypass valve  35  contains bypass valve slide  65 , which has an internal passage  82  with side port  84  that allows bypass conduit  27  connection to internal passage  82  when diaphragm  8  displaces bypass valve slide  65 , moving it upward to attain a bypass mode of operation for the fluid exchanger which is characterized by establishing fluid communication between flexible fluid exchange conduits  15  and  17  via bypass conduit  27  through check valve  34 , which removes the diaphragm tank assembly  3  from the fluid flow into and out of the hydraulic system being serviced.  
         [0028]     Diaphragm  8  divides the interior of the diaphragm tank assembly  3  into fresh fluid chamber  43  and used fluid chamber  45 . Bypass valve  35  has an automatic air vent  85  connected to it. Automatic air vent  85  bleeds off air unintendedly entering chamber  43  without leaking fluid from fresh fluid chamber  43 . A bypass valve of the same design was disclosed in U.S. Pat. Nos. 6,082,416 and 6,267,160, each to Viken and each being incorporated by reference herein.  
         [0029]     Tank top half  59  has position sensor  49  with a pair of leads  60  which are connected in series to a red indicator light, a warning tone, and a source of electric current (not shown but disclosed in U.S. Pat. No. 6,082,416 to Viken) such that when diaphragm  8  reaches its uppermost position conforming to tank top half  59  it activates the position sensor  49  and turns on the red indicator light and warning tone indicating to the operator that diaphragm tank assembly  3  is essentially filled with used fluid.  
         [0030]     Tank bottom half  62  has position sensor  53  with pair of leads  61  which are connected in series to a green indicator light and a source of electric current (not shown but disclosed in U.S. Pat. No. 6,082,416 to Viken) such that when diaphragm  8  reaches its lowermost position conforming to tank bottom half  62 , it activates the position sensor  53  and turns on the green indicator light and indicates to the operator that the diaphragm tank assembly  3  is essentially filled with fresh fluid.  
         [0031]     A number of different rubber compounds can be used to construct diaphragm  8 . Such compounds should be resistant to the effects of the particular hydraulic fluids that the fluid exchanger will be handling during the fluid exchanges. There are a number of different methods of constructing diaphragms, including molding with or without an integral reinforcing fabric. In the present invention diaphragm  8  is molded without any integral reinforcing fabric and is comprised of a nitrile-type compound.  
         [0032]      FIG. 2  is a schematic view of the automatic flow alignment valve  2  operating in an initial random, but non-aligned, not-locked mode of operation, characterized by valve  165  being position in a non-aligned position relative to the flow of used fluid being discharged from the hydraulic circuit accessed for fluid exchange.  FIG. 3  is an exploded view of the integral parts of the automatic flow-aligning valve assembly  2  and locking mechanism  1 . Automatic flow-aligning valve assembly  2  includes multi-port valve body  184  containing movable valve  165 .  
         [0033]     A valve slide  165  is contained within valve bore  178  of automatic flow-aligning valve assembly  2 . Valve bore  178  is threaded at each end to receive hydraulic hex plug  63  at its leftmost end and hex plug  64  at its rightmost end, both in this case being fitted with an integral O-ring for suitable sealing (not shown).  FIG. 3  shows valve slide  165  having left internal fluid passage  289  which has one end near the left side of valve slide  165  at left transverse cutout  296  and terminates at an end near right transverse fluid port  290  which is located between left land  294  and center land  293 .  FIG. 3  shows valve slide  165  to be constructed to have right internal fluid passage  292  which starts at the right side of valve slide  165  at right transverse cutout  297  and terminates at left transverse fluid port  291  which is located between right land  295  and center land  293 . Left internal fluid passage  289  is not connected to the right internal fluid passage  292 , and therefore no fluid can pass through either passage to the other (as shown in  FIG. 2 ). Valve bore  178  has left chamber  157  which is between hex plug  63  and valve slide assembly  165 , and has right chamber  155  which is between hex plug  64  and valve slide assembly  165 .  
         [0034]     As shown in  FIG. 2 , locking mechanism  1  has an operating rod containment tube  168  which is in this case constructed of an essentially magnetic neutral metal, brass in this instance. Various types of plastics and other essentially non-magnetic materials could be alternatively used. Operating rod containment tube is inserted through an internal bore  188  of solenoid coil  6  which has a suitably sized male threads at both ends, with the one at its lower end screwed into threaded port  171  of operator rod containment assembly  4  at one end and suitably sealed, with an anaerobic hydraulic sealer used in this case. At its other end operating rod containment tube  168  is screwed into threaded port  170  of valve body  184  of automatic flow alignment valve  2  and suitably sealed, with an anaerobic hydraulic sealer.  
         [0035]     Operator rod containment assembly  4  has female threaded port  173  to which check valve  86 , which has a male thread at one end, is screwed into busing  174 , and busing  174  is then turned into threaded port  173  of operator rod containment assembly  4 . Solenoid coil  6  has an internal passage  188  through which operator rod containment tube  168  can be inserted ( FIG. 3 ). Rod operator assembly  166  is comprised of two integral parts which are counter threaded at their meeting ends for easy assembly, with an operator rod top half  176  and an operator rod bottom half  177  (as shown in  FIG. 2 ). Rod operator assembly  166  (shown in exploded view in  FIG. 3 ), has top crown  175  which has vent  285  and vent  286  cutout of it on either side, allowing any fluid pressure differential on either side of top crown  175  to be quickly vented and equalized. Operator rod top half  176  is constructed of a magnetic material, such as iron. Operator rod bottom half  177  is constructed of a non-magnetic material, such as brass.  
         [0036]     In addition, locking mechanism  1  as shown in  FIG. 2  can incorporate an interiorly placed diaphragm seal constructed of a nitrile type compound. This seal can be placed above operator rod crown  175  inside operator rod containment assembly  4 . This diaphragm seal when arranged above rod operator assembly  166  inside rod operator containment assembly  4  and fresh fluid conduit  25 , will allow fresh fluid delivered from fresh fluid chamber  43  to actuate the locking mechanism and keep it locked during the fluid exchange, as long as all the fresh fluid being conducted to the automatic flow-aligning valve assembly  2  passes into the top of operator rod containment assembly  4  on the way to the automatic flow-aligning valve assembly  2  and can only pass through it if the rod operator assembly of  FIG. 2  moves into and remains in its locked position. This allows automatic flow-aligning valve assembly  2  with such a modified fresh fluid operated locking mechanism to be easily interconnected into the two fluid exchange hoses of any fluid exchanger which has a pair of fluid exchange hoses, one of which is a fresh fluid delivery hose and the other of which is a used fluid discharge hose, transforming the points at which each hose is connected to opened hydraulic circuit being serviced to become bi-directional fluid exchange hoses. This transformation of each of the fluid exchange hoses to bi-directional capability allows each to serve as a fresh fluid supply hose or a used fluid discharge hose for the hydraulic circuit, as will be determined by the direction of fluid flow in the hydraulic service being connected to for service, which is typically unknown at the time at which that circuit is opened and the hoses are connected (one each) to a side of the opened hydraulic circuit to be serviced.  
         [0037]      FIG. 3  shows operator rod containment tube  168  having internal bore  187  to which rod operator assembly  166  is inserted and fits relatively loosely, able to easily slide up and down within the bore, allowing fluid pressure to quickly dissipate between the internal bore  187  and rod operator assembly  166 .  
         [0038]     Referring to  FIG. 2 , valve body  184  has an internal rod port  183  which allows the operator rod bottom half  177  to slide within and through to fit between either pair of lands of valve slide assembly  165 , center land  293  and right  295 , or between center land  293  and left land  294 , depending on whether valve slide  165  is in its leftmost or rightmost position respectively. Operator rod bottom half  177  can be moved into its locked position located between either of these sets of lands under power of the solenoid coil  6  when it is provided electrical current and draws the operator rod top half  176  downward, under power of the magnetic force provided by solenoid coil  6 . During assembly, operator rod assembly  166  is inserted through return spring  167 , into and through an internal cavity  172  of rod operator containment assembly  4 , and into and through operator rod containment tube  168 . Rod operator assembly  166  can move back into its unlocked position when electrical current is removed from solenoid coil  6 , which results when flow switch  7  stops providing signal to relay  9  to provide current to solenoid coil  6 . When current is removed from solenoid coil  6 , return spring  167  moves operator rod assembly  166  back into its unlocked position. Alternatively, for some low pressure hydraulic circuits, if locking mechanism  1  is positioned on the bottom side of automatic flow-aligning valve assembly  2 , return spring  167  can be eliminated, with gravity providing the power to move rod operator assembly  166  back into position.  
         [0039]      FIG. 3  shows valve body  184  to have five ports machined to its bottom side which penetrate from the outside into valve bore  178 , and these include port  50  and port  52  to which flexible fluid exchange hoses  15  and  17  of  FIG. 1  are connected respectively. Fresh fluid port  54  and fresh fluid port  56  are both connected to fresh fluid conduit  25  of  FIG. 1 . Used fluid outlet port  58  is connected to used fluid conduit  23  of  FIGS. 1 and 2 . These port connections are made using conventional sealing methods such as inserting threaded hose barbs into female threads cut into each port (not shown but known in the art), with the conduits and hoses then connected to the hose barbs by conventional means such as hose clamps or self-locking methods known in the art.  
       OPERATION OF THE PREFERRED EMBODIMENT  
       [0040]     The preferred embodiment of  FIG. 1  is interconnected to the hydraulic fluid circuit that is to be serviced, which in this instance is a fluid cooling line of an automatic transmission (not shown, but understood in the art). The fluid cooling line is opened, establishing two ports or orifices, each of which will serve as a suitable connection point for one of the flexible fluid exchange conduits  15  and  17  which in this case are constructed of flexible rubber which is resistant to automatic transmission fluids. In this case as shown in  FIG. 1 , the particular connections made to these orifices are flexible fluid exchange conduit  17  connected to the higher pressure side (discharge side) of the cooling circuit of the automatic transmission, and flexible fluid exchange conduit  15  connected to the lower pressure side (return side) of the cooling circuit. In  FIG. 1 , fluid flow is represented by use of arrows. The fluid exchange system operator does not need to identify or know which of the two orifices provides access to either the lower pressure, return side of the cooling circuit, or the higher pressure, outlet side of the cooling circuit in order to operate the system and institute a fluid exchange procedure.  
         [0041]     The fluid exchange system  10  aligns itself with the direction of fluid flow in the hydraulic circuit being serviced. As the engine of the vehicle is started and operated in park, neutral or drive (with the parking brake applied) the automatic transmission is rendered operative to flow fluid through its cooling circuit. This causes used fluid to be discharged into and through flexible fluid exchange conduit  17 , then into right valve chamber  155  of the automatic flow-aligning valve assembly  2 . Valve slide  165  begins to be moved toward and into the left chamber  157  of valve bore  178  as shown in  FIG. 4 , which depicts the operation of automatic flow-aligning valve assembly  2  in a transitional mode of operation before valve slide  165  has moved into proper flow alignment position. At the same time any pressure differential between used fluid outlet port  58  and the topside of operator rod crown  175  is equalized through check valve  86  and balance port  28  ( FIG. 2 ).  
         [0042]     The fluid pressure provided by the accessed cooling circuit of the automatic transmission through flexible fluid exchange conduit  17  continues to move valve slide assembly  165  toward and into left chamber  157  until it can go no further, at which time valve slide  165  is properly aligned with the operator rod bottom half  177  as shown in  FIG. 5 . When valve slide  165  has become moved into its proper alignment position, used fluid flows from used fluid outlet port  58  into and through used fluid conduit  23 , through check valve  37 , then into port  31  of diaphragm tank assembly  3  to be deposited in used fluid chamber  45  (as shown in  FIG. 1 ).  
         [0043]     This causes used fluid chamber  45  to increase in volume, which causes diaphragm  8  to be displaced by the same volume, which then results in an essentially equivalent volume of fresh fluid being pumped out of fresh fluid chamber  43  into and through bypass valve slide  65  through its side port  94  and into and through fresh fluid conduit  29 . Fresh fluid then flows through flow switch  7 , through port  54  ( FIG. 2 ), through left transverse fluid port  290 , through left internal fluid passage  289 , into left chamber  157 , through port  50 , and then into flexible fluid exchange conduit  15  to be delivered into the lower pressure side (return side) of the cooling circuit of the automatic transmission having its fluid exchanged.  
         [0044]     When fluid begins to flow through flow switch  7 , an electrical switch (not shown) closes and provides an electrical signal to relay  9  that activates to provide power to boost pump  5  and solenoid coil  6 . As boost pump  5  is activated to pump fluid, solenoid coil  6  is energized to move rod operator assembly  166  ( FIG. 2 ) downward into and through internal rod port  183  to rest between right land  295  and center land  293  ( FIG. 5 ). The space between right land  295  and center land  293  is in proper position to receive rod operator assembly  166  because valve slide  165  has already moved into proper position before fluid flows through flow switch  7  to cause solenoid coil  6  to become energized and activate boost pump  5 . As long as fluid continues flowing through flow switch  7 , rod operator assembly  166  is held in position and blocks any movement of valve slide  165  which could occur due to the operation of boost pump  5 , which could raise the fresh fluid pressure in left chamber  157  of automatic flow-aligning valve assembly  2  to be greater than the used fluid pressure at its right chamber  155 .  
         [0045]     Referring to  FIG. 2 , if the fluid pressure in left fluid chamber  157  is greater than the fluid pressure in right chamber  155 , then valve slide  165  will move into its furthermost right position unless locking mechanism  1  has been operated to attain its properly locked position. Alternatively, if the fluid pressure in right fluid chamber  155  is greater than the fluid pressure in left fluid chamber  157 , then the valve slide  165  will move into its furthermost left position. Once rod operator assembly  166  is pulled into and through internal rod port  183  and held there by force of energized solenoid coil  6 , automatic flow-aligning valve assembly  2  is in locked position characterized by rod operator assembly  166  blocking any potential shift of valve slide  165  out of its proper alignment position. This proper alignment position is initially determined by the direction of fluid flow in the hydraulic circuit being serviced in relation to the particular random choice made by the operator for connecting the flexible fluid exchange conduits to the two orifices made available by opening the hydraulic circuit. In vehicular fluid exchanges, valve slide  166  moves into proper alignment position before used fluid flows out of automatic flow-aligning valve assembly  2  into used fluid conduit  23 . In even those which involve higher flow transmissions which operate at much higher pressures, a delay in the activation of flow switch  7  would result from the wall flexibility of in the conduits of the present invention in its preferred embodiment because the flexible used and fresh fluid conduits  15  and  17  respectively are constructed of a nitrile based rubber hose which is resistant to automatic transmission fluid.  
         [0046]     Conduit  15 ,  17  flexibility typically allows a small amount of wall expansion which can provide enough delay in the pressure increase in fresh fluid conduit  29  transmitted to port  54  of automatic flow-aligning valve assembly  2  for the solenoid coil  6  to move the operator rod assembly  166  downward to place the lowermost end of operator rod bottom half  177  into proper locked position before the boost pump is activated. This assures that the valve slide assembly  165  will stay in proper fluid flow alignment position when the boost pump is activated to increase the pressure of the fresh fluid to be greater than the pressure of the used fluid, which could increase the fresh fluid pressure in chamber  157  to be greater than the used fluid pressure of chamber  155  ( FIG. 5 ) which would otherwise cause valve slide  165  to move towards its rightmost position.  
         [0047]     If the internal fluid exchange conduits are constructed of a hard, non-expanding material such as steel or aluminum tubing, or the pressures of the hydraulic fluid circuit being serviced with a fluid exchange are relatively high, an electronic time delay relay can be used to delay the activation of locking mechanism  1  and boost pump  5  to assure that the valve slide  165  has reached its proper flow alignment position. For example, such electronic time delay relay can be interconnected to either signal wire  44 , or to signal wire  47  of flow switch  7 , or within relay  9 , or to hot wire  46  of boost pump  5 .  
         [0048]     As shown in  FIG. 5 , valve slide  165  has moved into its left most position establishing fluid flow alignment. This direction to which valve slide  165  moves is based on the direction of fluid flow in the hydraulic fluid circuit being accessed in coordination with the particular selection of which flexible fluid exchange conduit  15  or  17  is connected to the higher pressure side of that circuit. In this case the operator has connected flexible fluid exchange conduit  17  to the higher pressure (discharge) side of that hydraulic circuit and flexible fluid exchange conduit  15  to the lower pressure (return) side of that circuit.  
         [0049]     As shown in  FIG. 5 , once valve slide  165  has moved into its left most position, it has established fluid flow alignment, the used fluid will flow into the used fluid chamber  45  ( FIG. 1 ), thus displacing an essentially equivalent amount of fresh fluid from fresh fluid chamber  43 . Once this occurs, fresh fluid will flow into and through fresh fluid conduit  29  to flow through flow switch  7 , thus activating flow switch  7  which results in providing an electrical signal to relay  9  which in turn provides current to energize solenoid coil  6  and to operate boost pump  5  as shown in  FIG. 1 . Referring to  FIG. 5 , as used fluid flows through port  58  and into used fluid conduit  23 , it also exerts the same fluid pressure to internal rod port  183  of valve body  184 , which could create a pressure differential on both sides of the rod operator assembly  166 , with the higher pressure on its lower side, thus potentially keeping it in its upper most position. Any tendency for there to be a pressure differential impacting rod operator assembly  166  to keep it in its uppermost position is neutralized because this pressure differential has been dissipated and equalized through a venting system and check valve  86 .  
         [0050]     Referring to  FIGS. 2 and 3 , this venting system is comprised of the gap between the operator rod assembly  168  and the internal bore  187  of operator rod containment tube  168  and internal port  183 , through the vents  285  and  286  of top crown  185  of rod operator assembly  166 , through balance port  28 , and through used fluid conduit  23 . This venting system for rod operator assembly  166  makes it essentially pressure neutral, allowing it to move freely to lock valve slide  165  in automatic flow-aligning valve assembly  2  in its proper flow alignment position when solenoid coil  6  is energized, and to also able to return under the power of return spring  167  when electrical current is removed from solenoid coil  6  after the fluid stops flowing through the fluid exchange system which occurs when the when the operator turns off the engine of the vehicle (in a vehicular fluid exchange) or turns off the hydraulic supply pump (in other industrial hydraulic systems).  
         [0051]     As shown in  FIG. 1 , when boost pump  5  is operated it can increase increases the fresh fluid pressure in fresh fluid conduit  29  to be greater than the fluid pressure of used fluid conduit  23  by applying lower pressure to the top side of check valve  86  than to used fluid out port  58 . Because check valve  86  does not allow flow upward through it, any additional low pressure at the topside of check valve  86  prevents that additional low pressure to be communicated through it to urge rod operator assembly  166  upward.  
         [0052]     It should be noted that in some lower pressure applications, use of the balance port  28  or any connection of operator rod containment assembly  4  to used fluid conduit  23  would not be required, since the remaining part of the venting system would be adequate to prevent enough used fluid pressure differential from diminishing the movement of rod operator assembly  166  when force is being applied to rod operator assembly  166  by solenoid coil  6 .  
         [0053]     Referring to  FIG. 5 , once valve slide  165  has moved into its left most position establishing fluid flow alignment and is locked into its proper flow alignment position by the energizing of solenoid coil  6  as shown in  FIG. 5 , used fluid flow into used fluid chamber  45  ( FIG. 1 ) is boosted by boost pump  5  and system  10  is placed it its operational, fluid pumping mode. If the hydraulic system being serviced with a fluid exchange is a higher flow type system which pumps used fluid into used fluid conduit  23  at a higher flow rate than provided by boost pump  5 , then used fluid flows through check valve  37  ( FIG. 1 ), which prevents the fluid exchange from being slowed needlessly down. On the other hand, if the hydraulic system being serviced with a fluid exchange is a lower flow type system which pumps used fluid into used fluid conduit  23  at a flow rate less than provided by boost pump  5 , then check valve  37  closes and prevents the used fluid provided by pump  5  from being bypassed back into used fluid conduit  23  and into pump head  18  of boost pump  5 , which could slow or even potentially stop the fluid exchange.  
         [0054]     Boost pump  5  in this depiction of  FIG. 1  is arranged intermediate between used fluid conduit  23  and used fluid conduit  26 , therefore before the used fluid enters used fluid port  31  of diaphragm tank assembly  3  to enter used fluid chamber  45 , it either passes through check valve  37  or is pumped through boost pump  5 . Alternatively boost pump  5  could be arranged intermediate to fresh fluid conduit  29 . This would also function effectively.  
         [0055]     Referring to  FIG. 1  the fluid exchange system  10  will continue until the engine of the vehicle is turned off to render the automatic transmission inoperative, or until fresh fluid chamber  43  reaches its uppermost position in diaphragm tank assembly  3 , at which time it moves bypass valve slide  65  into its upper position, which in turn positions internal passage  82  of bypass valve slide  65  to allow fluid to flow from used fluid conduit  26 , through check valve  34  and into bypass conduit  27 , through bypass valve  35  and into fresh fluid conduit  29 . Thus, when bypass valve slide  65  is moved by diaphragm  8  into its upper most position, the fluid exchange system  10  is shifted into bypass mode, allowing the fluid being discharged from the hydraulic circuit to be immediately returned (without exchange) back into the inlet (return) side of the hydraulic system. This feature allows the operator of the fluid exchange system freedom of movement away from the vehicle during the exchange procedure without fear of vehicle damage. In addition, when diaphragm  8  reaches its uppermost position, it activates position switch  49  which then energizes a red LED and warning tone which notify the operator that the fresh fluid supply of fresh fluid chamber  43  is depleted and the fluid exchange system is in bypass mode.  
         [0056]     Before another fluid exchange is instituted for another hydraulic system, the operator should determine which type of new fluid should be used to fill fresh fluid chamber  43 . In this example, another vehicle with an automatic transmission with a circulating hydraulic fluid system, an external cooling circuit. In order to fill fresh fluid chamber  43 , diaphragm tank assembly  3  must be recharged, which involves the pumping of fresh fluid into fresh fluid fill port quick connect  30  accompanied by the simultaneous venting into a waste receiver of the used fluid of used fluid chamber  45  through used fluid discharge port quick connect  32 .  
         [0057]     During the recharging of diaphragm tank assembly  3 , the volume of the used fluid being discharged is essentially equivalent to the volume of fresh fluid being pumped in because it is being displaced by the fresh fluid being pumped into chamber  43 . As fresh fluid is pumped into fresh fluid fill port quick connect  30 , it flows into the top of bypass valve  35  and through bypass valve slide  65  to enter fresh fluid chamber  43 . Check valve  34  provided to bypass conduit  27  prevents fresh fluid from flowing out of used fluid discharge port quick connect  32  during the recharge.  
         [0058]     This recharging of diaphragm tank assembly  3  can be instituted by the operator connecting a separate used fluid drain hose (not shown) to used fluid discharge port quick connect  32  which has its own compatible quick connect at that connection end and then placing its other end to discharge into a suitable waste receiver for proper disposal later. The operator also connects a pressurizable source of fresh fluid to with a quick connector compatible with fresh fluid fill port quick connect  30 . Then the operator pumps fresh fluid from this fresh fluid source into fresh fluid fill port quick connect  30  while used fluid is simultaneously discharged. This recharging is continued until fresh fluid chamber  43  is full and used fluid chamber  45  is essentially emptied. A complete recharge is characterized as the movement of diaphragm  8  to its lowermost position possible in diaphragm tank assembly  3 . When this lowermost position of diaphragm  8  is attained, then it activates position sensor  53  that in turn energizes a green LED, signaling the operator that the recharge procedure is complete and the unit is now ready to institute another fluid exchange procedure as soon as connections to fresh fluid fill port quick connect  30  and used fluid discharge port  32  are removed.  
         [0059]     Alternatively, the used fluid position sensor  53  can be used to provide a signal to relay  9  to control current to operate boost pump  5  as soon as diaphragm  8  is moved slightly upward from its most downward position, with the fresh fluid position sensor  49  used to provide signal to relay  9  to remove the current to boost pump  5 .  
         [0060]      FIG. 6  shows an alternative form of an automatic flow alignment valve  413  with dual locking mechanisms connected to valve block  414 . This form can be substituted for the preferred form shown in  FIGS. 1-5  and used in almost any other fluid exchange system which utilized electrical current and has two flexible fluid exchange conduits, one for dispensing fresh fluid to the hydraulic circuit having a fluid exchange and the other one for receiving used fluid from that hydraulic circuit. Two separate locking mechanisms, right locking mechanism  401  and left locking mechanism  402  are connected to automatic flow alignment valve  413 . Both locking mechanism  401  and locking mechanism  402  are internally configured the same as the locking mechanism  1  as shown in  FIGS. 1-5 , operate according to the same principles, and are arranged on valve block  414  as shown in  FIG. 6 .  
         [0061]     Locking mechanisms  401  and  402  each contain a rod operator assembly, rod operator assembly  405  and rod operator assembly  406  respectively. Used fluid discharged from the hydraulic circuit being serviced is flowing through flexible fluid exchange conduit  17  (shown in  FIG. 1 ) and into port  452  of valve block  414  and has already moved valve slide  465  into proper flow alignment position after which used fluid flows out of port  458 . Fresh fluid is flowing from fresh fluid conduit  425  through flow switch  410 , through fresh fluid conduit  427 , into fresh fluid inlet port  454  of valve block  414 , and out of port  450  and into flexible fluid exchange conduit  15  (shown in  FIG. 1 ). Valve block  414  has an internal bore  478  which has hex plugs  463  and  464  screwed into each of its ends which are provided with suitably matched female threads. Bore  478  has two internal access ports, ports  411  and port  412  provided which allow rod operator assemblies  405  and  406  respectively to intersect and lock valve slide  465  when either one is moved downward by activation of their corresponding solenoid coils  407  or  408  respectively.  
         [0062]     Flow switch  410  has been activated by the fresh fluid flowing through it and has triggered relay  9  ( FIG. 1 ) which in turn has provided current to boost pump  5  ( FIG. 1 ) and to both solenoid coils  407  and  408 . Only rod operator assembly  405  can move downward into position since valve slide  465  blocks complete extension downward of rod operator assembly  406 . The downward movement of rod operator assembly  405  into proper locked position will prevent valve slide  465  from moving to its right if the boost pump  5  increases the fresh fluid pressure in fresh fluid conduit  425  to be greater than the pressure in used fluid conduit  423  at automatic alignment valve  413 .  
         [0063]     A balance conduit  428  is connected at one end to check valve  418 , and at another end to balance port  429  of an operator rod containment assembly  404  of locking mechanism  402 , and also connected at another end to balance port  430  of an operator rod containment assembly  403  of locking mechanism  401 .  
         [0064]     In  FIG. 6 , there are two separate flow switches, flow switch  409  and flow switch  410 . Flow switch  409  is connected at one end to fresh fluid conduit  426  that is in turn connected to fresh fluid inlet port  456 , and at its other end to fresh fluid conduit  425 . Flow switch  410  is connected at one end to fresh fluid conduit  427  that is in turn connected to fresh fluid inlet port  454 , and at its other end to fresh fluid conduit  425 . When this automatic flow alignment valve  413  with dual locking mechanisms  401  and  402  and dual flow switches  409  and  410  is substituted for automatic flow alignment valve  2  with locking mechanism  1  and flow switch  7  of  FIG. 1 , fresh fluid conduit  425  of  FIG. 6  is connected to fresh fluid conduit  29  of  FIG. 1 , and balance conduit  428  is connected to check valve  418  at one end, to balance port  429  at an other end, and balance port  430  at another end.  
         [0065]     Additional forms using other multiple fluid flow valves configured to provide automatic alignment can be fitted with associated multiple locking devices can be utilized and do not depart from this novel art. The locking mechanisms can be configured to operate from the power provided by fresh fluid or by power of an electric solenoid coil in combination with an electric flow switch and relay. For example, an automatic fluid flow alignment structure comprised of 4 separate check valves such as disclosed in U.S. Pat. No. 5,806,629 to Dixon et al, or an automatic fluid flow alignment structure comprised of a shuttle valve and two check valves such as disclosed in U.S. Pat. No. 6,267,160 to Viken, can have each valve provided with a locking device.  
         [0066]     Pairs of check valves can utilize combination locking mechanisms based on the locking mechanism herein disclosed can be arranged and sealed between two check valves each, able to lock one when activated, and locking the other in default. These pairs of check valves then can share a single locking mechanism with a two sided operator rod assembly, which is operated in a first direction by default under spring power, and can operate in the opposite direction under power provided by the solenoid coil after a signal is generated to direct the proper operation of such combination locking device. This allows the use of a boost pump to pump the fresh fluid at a higher pressure than the incoming used fluid from the accessed hydraulic circuit, which would otherwise disrupt the function of the automatic flow alignment valve structure.  
         [0067]     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Technology Classification (CPC): 5