Abstract:
A nurse vehicle carries a supply of liquid chemicals or fertilizer for being applied by a sprayer vehicle. A fluid transfer conduit of the nurse vehicle has an end defined by a receptacle that is selectively connected to a complementary dimensioned insert defining an end of a fluid intake conduit of the sprayer vehicle. The receptacle and insert define a coupler assembly that includes an inflatable seal that surrounds the insert and locks the insert and receptacle together when inflated. Flow through the coupler assembly is controlled by first and second poppet valves, which are normally closed preventing flow through valve bodies of the receptacle and insert. Selective inflation of the seal and opening and closing of the poppet valves is automatically controlled in accordance with sequencing logic of an electronic controller so the seal is inflated before the valves are opened and remains inflated until the valves are closed.

Description:
FIELD OF THE INVENTION 
     The present invention relates to agricultural sprayers, and more specifically relates to a valve coupler arrangement for facilitating the transfer of fluid from a nurse tank to the sprayer. 
     BACKGROUND OF THE INVENTION 
     It has recently become known to equip a sprayer vehicle and a nurse tank vehicle with a fluid coupler arrangement by which a fluid transfer conduit extending from the nurse tank can be manually or automatically connected to an intake fluid conduit leading to a sprayer tank. After making the connection, the operator opens a series of valves to establish a fluid path permitting fluid to flow from the nurse vehicle tank to the sprayer vehicle tank or tanks. Such a coupling arrangement is described in U.S. patent application Ser. No, 10/284,002, flied 30 Oct. 2002 and published under No, 200400484551, and now issued as U.S. Pat. No. 7,503,510, granted Mar. 17, 2004. 
     After the fluid tank or tanks of the sprayer vehicle have been refilled, the operator must close valves and disconnect the fluid coupler interconnecting the transfer and intake conduits in a manner which prevents or limits fluid chemicals from spilling onto the ground. One drawback of current large fittings and valves that are required for quickly transferring fluid chemicals from the nurse tank to the sprayer tank or tanks is that they permit significant spillage of the chemicals. 
     The problem to be solved then is to provide a coupler arrangement between the transfer and intake conduits of the nurse and sprayer vehicles which permits a relatively quick transfer of fluid chemicals while minimizing spillage of such chemicals. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a coupler arrangement for selectively connecting a nurse tank fluid transfer conduit to, and disconnecting the transfer hose from, a sprayer fluid intake conduit. 
     An object of the invention is to provide a coupler arrangement including a first coupler section connected to an end of a nurse tank fluid transfer conduit, and a second coupler section connected to an end of fluid intake conduit of a sprayer, with the first and second coupler sections being designed for cooperating, during being coupled together and uncoupled from each other, so as to eliminate any significant spillage of fluid chemicals. 
     The foregoing object is achieved by a coupler arrangement wherein the first and second coupler sections each include a hollow body defining a fluid passage, with the fluid passage of the first coupler section including a discharge opening normally closed by a first flow control valve such as a first poppet valve, which is spring loaded, and with the fluid passage of the second coupling section including an inlet opening normally closed by a second flow control valve such as a second poppet valve which is loaded to its closed position by the spring acting on the first poppet valve when a cylindrical insert defined at the end of one of the first and second coupler sections is seated within a cylindrical receptacle defined at the end of another of the first and second coupler sections, with a remotely operable power actuator being located within the hollow body of the second coupler section and connected to the second poppet valve so that the actuator can be selectively operated to open the first and second poppet valves against the spring load. The coupler section which defines the insert includes an annular seal groove containing an inflatable seal which may be selectively inflated for preventing leakage and establishing a tight friction lock between the insert and the receptacle once the insert is property seated in the receptacle. A proximity device is provided which senses when the insert is properly located in the receptacle and sends a signal to the operator prior to the inflation of the seal. Once the seal is inflated, the actuator is actuated for effecting the opening of both poppet valves so as to establish an uninterrupted fluid path through which fluid can flow from the nurse vehicle to the sprayer vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view showing a nurse vehicle fluid discharge conduit coupled to a sprayer vehicle inlet conduit over a releasable coupler arrangement. 
         FIG. 2  is a side view of the coupler arrangement with the coupler sections being shown in a separated condition. 
         FIG. 3  is a vertical, longitudinal sectional view of the coupler arrangement shown in  FIG. 2 . 
         FIG. 4  is a view like  FIG. 3 , but showing the coupler sections seated together, with the poppet valves closed. 
         FIG. 5  is a view like  FIG. 4 , but showing the poppet valves opened. 
         FIG. 6  is a schematic representation of an electro-hydraulic control circuit for controlling the opening of the poppet valves incorporated in the coupler arrangement. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIG. 1 , there is shown a self-propelled sprayer vehicle  10  positioned adjacent a nurse vehicle  40  during a refill operation. The sprayer vehicle  10  includes a frame  12  supported on front and rear pairs of ground wheels  14  and  16 , respectively. Mounted on a central region between opposite ends of the frame is an operator&#39;s cab  18  which contains all of the controls (not shown) for controlling the operation of the sprayer vehicle  10  including the routing of fluid to spray nozzles of a spray boom  20  supported at a rear end of the frame  12 . Fluid to be sprayed on a crop and/or the ground is contained in a tank  22  mounted on the frame  12  behind the cab  18 , with it to be understood that the tank  22  is merely representative and that a plurality of sprayer tanks could be provided. A fluid level sensor  23  is provided on the tank  22  for monitoring the level to which the tank is filled. A fluid intake conduit  24  is coupled for filling the tank  22 , and located in the conduit is a variable speed, high capacity, variable displacement load or transfer pump  26  serving for refilling the sprayer tank  22 . A separate pump (not shown) is provided for drawing fluid from the tank  22  and supplying this fluid to the spray boom  20 . 
     In order to maximize the operation of the load pump  26  for each of different plumbing configurations that typically might be encountered when refilling from different nurse tanks, the operation of the pump  26  is monitored. Specifically, the operation of the load pump  26  is monitored by a tachometer  28  coupled to the pump drive shaft, a flow detector  30  located at the output of the pump, a vacuum detector  32  located at the input of the pump and an accelerometer  33  coupled to a housing location of the pump for sensing pump vibration. All of the sensed or monitored pump conditions provide information to an automatic control arrangement and/or to a visual display so that the control arrangement may automatically operate or the operator may intervene to reduce the displacement of the pump  26  in the event that the sensed or monitored pump conditions indicate an impending pump cavitation condition. Of course, pump displacement may be increased when no impending cavitation condition is monitored. 
     The nurse vehicle  40  may be of any variety of known configurations, but is here shown in the form of a trailer having front and rear sets of ground wheels  42  and  44 , respectively, which are normally interconnected by a framework, not shown, which supports a trailer bed  46  on which is positioned a large nurse tank  48 , which in many cases would contain a supply of water, and a smaller nurse tank  50  which would contain a concentrated chemical for being mixed with the water, for example. A fluid transfer conduit  52  is coupled directly to the nurse tank  48  and is coupled to the smaller nurse tank  50  by a branch conduit  54 . The fluid transfer conduit  52  contains a first flow meter  56  located just downstream from the larger nurse tank  48 , while a second flow meter  58  is located in the branch conduit  54 , with the flow meters  56  and  58  acting to ensure that a correct mixture of the fluids from the tanks  48  and  50  is transferred to the sprayer vehicle tank  22 . 
     As illustrated, the fluid intake conduit  24  of the sprayer spray vehicle  10  and the fluid transfer conduit  52  of the nurse vehicle  40  are interconnected by a coupler assembly  60  including first and second separable coupler components, namely a receptacle indicated generally at  62  and an insert indicated generally at  64 . With reference to fluid flowing in a direction from the fluid transfer conduit  52  to the fluid intake conduit  24 , the receptacle  62  is connected to a downstream end of the transfer conduit  52  while the insert  64  is connected to an upstream end of the intake conduit  24 . Appropriate on-off valves (not shown) would be provided for respectively isolating the insert  64  from a remaining portion of the intake conduit  24 , and isolating the receptacle  62  from a remaining portion of the transfer conduit  52  when the coupler arrangement  60  is separated. 
     As can be seen in  FIGS. 2-5 , receptacle  62  comprises a generally cylindrical body  66  defining a flow passageway  68  there through. The body  66  comprises a flange  70  having an axially facing, annular mounting face  72  clamped, as by bolts  74 , against a similar mounting face  76  defined by a flange  78  of a funnel-shaped body extension  80  having its smaller end received in and secured to the transfer conduit  52 . The downstream end of the body  66  comprises an axially extending annular wall  82  having a cylindrical inner surface  84  joined to a radially extending annular surface  86  so as to define a receptacle for receiving an end of the insert  64 . 
     The receptacle  62  further includes a poppet valve  90  for sealing the flow passageway  68 . Poppet valve  90  includes a stem  92  joined to a head  94  having a periphery defining a sealing surface including a leading cylindrical/pilot section  96  joined to a small diameter end of a frusto-conical section  98 , with an o-ring seal  100  being located in a seal groove provided at a juncture of the two sections. The stem  92  is mounted for sliding axially within a bushing carried by a support member  102  fixed within the receptacle body  66 . A coil compression spring  104  is received on the poppet valve stem  92  and acts between the support member  102  and the head  94  so as to normally bias the sealing surface of the poppet valve head  94  against a mating valve seat  106  at a discharge end of the passageway  68 . An axial end face  108  of the poppet valve head  94  is a concave surface formed as a spherical segment and has an outer periphery which is substantially coplanar with the receptacle surface  86  when the poppet valve  90  is closed, as shown in  FIG. 4 . 
     The insert  64  includes a generally cylindrical body  110  defining a flow passageway  112  there through. A downstream end region of the body  110  is defined by a mounting flange  114  having an axially facing mounting surface  116  on its downstream end disposed in confronting relationship to a mounting surface  118  of a mounting flange  120  located on the upstream end of an elongate, cylindrical body extension  122  including a downstream end section which is reduced in diameter and connected to the intake conduit  24 . A circular support plate  124  has an outer annular region clamped between the flanges  114  and  120  by a plurality of screws  125  extending through axially aligned holes provided in the flange  120  and plate  124  and received in threaded holes provided in the flange  114 . The support plate  124  is provided with a plurality of openings (not shown) for permitting the free flow of fluid from the downstream end of the passageway  112 . The upstream end of the insert body  110  is defined by an annular plate  126  fixed to a remainder of the body  110  by a plurality of screws  128 . The plate  126  cooperates with a reduced diameter portion of the body  110  to define an annular seal groove  130 , with an inflatable seal  132  being received in the seal groove  130 . An air fitting  134  is provided on the flange  114  of the insert body  110  and leads to air passage  136  which extends to the inflatable seal  132 . A cylindrical shoulder  138  is provided between the seal groove  130  and the flange  114  and is sized to fit snuggly within the cylindrical wall  82  of the receptacle body  66  when the insert body  110  is received in the receptacle of the receptacle body  66 , as shown in  FIGS. 4 and 5 . When so received, the insert  64  may be locked within the receptacle  62  by inflating the seal  132  by connecting a source of air pressure  133  to the fitting  134 . So as to insure that the insert body  110  is received in the receptacle of the receptacle body  66  prior to the seal  132  being inflated, a proximity sensor or sensors  139  is (are) provided in the flange  114  in axial alignment with an end face of the wall  82 , with the sensor(s)  139  generating a signal when the insert body  110  is properly received in the receptacle body  66 . 
     The insert  64  further includes a poppet valve  140  for sealing flow through the flow passageway  112  and a remotely controlled poppet valve actuator  142  is provided for selectively opening and closing the poppet valve. The valve actuator  142  comprises a single-acting, extensible and retractable air cylinder  144  (alternatively a hydraulic or electric actuator could be) disposed along a central axis of the body extension  122  and having a threaded tube  146  fixed to an upstream end cap, the tube  146  projecting through a hole provided centrally in the support plate  124  and receiving a nut  148  which is tightened against the plate  124  so as to fix the cylinder  144  to the support plate  124 . The poppet valve  140  comprises a stem defined by a piston rod  150  of the air cylinder  144 , and a head  152  screwed onto a threaded end of the piston rod. As considered relative to moving from an open position, illustrated in  FIG. 5 , to a closed position, illustrated in  FIGS. 2 and 3 , an outer periphery of the poppet valve head  152  defines a sealing surface including a leading cylindrical pilot section  154  followed by a frusto-conical section  156 . A seal groove containing an o-ring seal  158  is located at the juncture of the two sections  154  and  156 . The inlet end region of the flow passageway  112  is defined by a valve seat  160  configured to mate with the sealing surface of the valve head  152 . A coil compression spring  161  is received about the piston rod  150  internally of the air cylinder  144  and acts against a piston secured to the rod  150  so that a biasing force acts on the poppet valve head  152  in a direction tending to seat the sealing surface  156  against the valve seat  160  so as to prevent spillage when the coupling  60  is separated. Spillage of fluid when the coupling  60  is separated is also reduced by providing the valve head  152  with an axial face  162  in the form of a convex segment of a sphere sized to mate with the concave axial face  108  of the valve head  94  so that no fluid is trapped between the valve heads  94  and  152  that would escape when the coupling  60  is separated. It is to be noted that the shape of the axial faces of the valve heads  94  and  152  permits the heads to be slightly misaligned without affecting their tight engagement with one another. Also, it is to be noted that the valve head  94  of the poppet valve  90  associated with the receptacle  62  has a minor diameter which is just slightly larger than a major diameter of the valve head  152  of the poppet valve  140  associated with the insert  64  and that, when the poppet valves  90  and  140  are open, the distance between the circumference of the valve heads  94  and  152 , and a frusto-conical inner wall surface region of the receptacle body  66  is substantially constant so that a smooth flow occurs around the open valve heads. 
     An air supply/return conduit  164  is located within the insert body extension  122  and has opposite ends respectively coupled to an L-fitting  166  located adjacent one end of the cylinder  144  and a straight air fitting  168  extending through an end region of the insert body extension  122  adjacent the intake conduit  24 . Located at an opposite end of the cylinder  144  from the fitting  166  is another fitting (not shown) which is coupled to an air line leading to atmosphere for permitting the exhaust and intake of air during extension and retraction of the piston rod  150  so that an air lock preventing free movement of the piston rod does not occur. It will be appreciated that the source of air pressure  133  can be selectively coupled to an air line  180  (shown only in  FIG. 6 ) joined to the straight air fitting  168  in order to effect extension of the piston rod  150  and simultaneous movement of the poppet valve heads  94  and  152  from their seated closed positions, shown in  FIG. 4 , wherein fluid flow through the passage ways  68  and  112  is prevented, to their open positions shown in  FIG. 5 , wherein a continuous flow path is provided from the transfer conduit  52  to the intake conduit  24  by way of the flow passageways  68  and  112 . 
     Referring now to  FIG. 6 , there is shown a representative electro-pneumatic circuit  170  for controlling the operation of the pneumatic actuator  142  for controlling the opening and closing of the poppet valves  90  and  140 . It is to be noted that since the self-propelled sprayer vehicle  10  has an electric power supply, such as a battery, all of the powered components or elements of the coupler arrangement  60  are associated with the insert  64  so as not to require further coupler elements between the nurse tank vehicle and the sprayer vehicle. 
     The control circuit  170  includes an electronic controller  172  to which is connected the tank level sensor  23 , the proximity sensor(s)  139  and an indicator device  174 , such as a display device located in the sprayer vehicle cab  18 . An operator input device  175 , which may include an activation switch, for example, is provided by which the operator can send a start signal for initially arming the controller  172  for the automatic filling operation, with automatic filling beginning once a signal is received from the proximity sensor(s) indicating that the coupler assembly  60  is coupled. Also coupled to the controller  172  is an on board air system  176  including the source of air pressure  133  coupled to first and second electrically responsive control valves here depicted as solenoid valves  190  and  192 , respectively, for selectively either controlling the flow of air from the source of air pressure  133  to the inflatable seal  132  by way of an air supply line  178 , and to the pneumatic actuator  142  by way of the air supply line  180 . Additionally, the controller  172  is connected to an electrically responsive displacement control valve arrangement  182 , which, in turn is coupled to a displacement controller  184  of the variable displacement load pump  26 . The pump condition monitoring components, specifically the tachometer  28 , flow detector  30 , vacuum detector  32 , and accelerometer  33  are designated collectively as a pump condition monitoring arrangement  186  that is likewise coupled to the controller  172 , with it to be understood that respective pump condition signals are generated by each of the components. Further, it is to be noted that not all of the condition monitoring components are required for acquiring sufficient information for a determination of impending pump cavitation. 
     Assuming an operator is performing a spraying operation, the operator will become aware of the need to refill the tank  22  by a signal sent by the fluid level sensor  23  which is sent to the indicator device  174  at the operators station. The operator will then shut down the sprayer pump and drive the sprayer vehicle  10  to the staging area where the nurse tank vehicle  40  has been previously parked for refilling the sprayer tank  22 . 
     The operator will then arm the controller  172  for performing an automatic fill operation by hitting the activation switch of the input device  175 . The operator then takes steps to bring the coupler insert  62  and receptacle  64  of the coupler assembly  60  into axial alignment with each other and to move them together, with the insert  62  being located within the receptacle  64 . Upon the insert  62  becoming completely received in the receptacle  64 , the proximity sensor(s)  139  will send a coupled signal to a sequencing logic arrangement of the controller  172  so as to initiate the automatic fill operation. The sequencing logic circuit first acts to send a lock signal to a first solenoid-operated air valve  190  of the onboard air system  176  for causing the air valve to shift so that the source of air pressure  133  is automatically routed for effecting inflation of the seal  132 , thereby locking the coupler insert  62  and the receptacle  64  together. Following this, the sequencing logic circuit within the controller  172  sends an open signal to a second solenoid-operated air control valve  192  of the onboard air system  176  for causing the air valve to shift so that the source of air pressure  133  is automatically routed for effecting extension of the pneumatic actuator  142 , and, thus, opening of the poppet valves  90  and  140 . The sequencing logic contained in the controller  172  then acts to send a signal for actuating the appropriate solenoid of the electrically responsive displacement control valve arrangement  182  for causing the latter to control the flow of hydraulic fluid to the displacement controller  184  of the pump  26  so as to ramp-up displacement of the pump  26  so that it begins to transfer fluid from the nurse vehicle  40  to the sprayer vehicle  10 . 
     Pump operation is monitored by the tachometer  28 , flow detector  30 , vacuum detector  32  and the accelerometer  33 , with these devices sending respective signals to the controller  172 . In the event that the monitored or sensed operating condition of the pump  26  indicates that cavitation is impending, the controller  172  will send a signal to the electrically responsive displacement control valve arrangement  182  for causing the latter to route a control fluid signal to the displacement controller  184  of the pump  26  to cause the displacement to be decreased sufficiently to avoid cavitation. 
     Upon the sprayer tank  22  becoming filled, the fluid level sensor  23  will send a full signal to the controller  172  which then sends a ramp-down signal to the electrically responsive displacement control valve arrangement  182  which sends a fluid control signal to the displacement controller  184  of the pump  26  to decrease its displacement to zero. Shortly thereafter, the sequencing logic section of the controller  172  will receive a close signal and will terminate the open signal previously sent to the second solenoid-operated air control valve  192  of the on board air system so as to effect the venting of the air from the air line  180  thus permitting the springs  161  and  104  to act to close the poppet valves  90  and  140 . Subsequently, the sequencing logic section of the controller  172  will receive an unlock signal and will terminate the lock signal previously sent to the first solenoid-operated air control valve  190  of the air system so as to vent the air from the inflatable seal  132 . The indicator device  174  at the operator station will also receive the unlock signal and display the fact that the insert  62  and receptacle  64  of the coupler arrangement  60  are no longer locked together. The refill operation is then completed and the operator can separate the insert  62  from the receptacle  64  and drive the sprayer  10  away from the nurse vehicle  40  and return to the field to resume the spraying operation. 
     Thus, it will be appreciated that once the operator arms the control system for automatic refill operation and the controller receives a signal from the proximity sensor(s)  139  indicating that the insert  62  and receptacle  64  of the coupler arrangement  60  are coupled together, the remainder of the refill operation is automatic with a substantially leak-free coupling being established prior to the opening of the poppet valves  90  and  140 . Further due to the poppet valve heads  94  and  152  being respectively biased against the valve seats  106  and  160  by the springs  104  and  161 , and due to the close fit of the valve head faces  108  and  162  with each other during flow through the coupler arrangement  60 , no fluid escapes around, and no fluid is trapped between the valve heads when the poppet valves close immediately after ramp-down of the pump  26  after the sprayer tank  22  is filled, thus eliminating any spillage from this area when the coupler arrangement  60  is separated. 
     Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.