Abstract:
An apparatus and method for supplying virgin sealer and reclaim sealer to a sealer applicator. A closed loop path including a first fluid flow path is coupled between a source of virgin sealer and the applicator and includes a recirculation path from the applicator back to the source of virgin material. A reclaim sealer supply is coupled to the first fluid flow path. Valves open and close the virgin sealer supply and the reclaim sealer supply to alternately supply virgin sealer or reclaim sealer to the applicator. Whenever the first fluid flow path contains reclaim sealer, a valve blocks flow to the recirculation path to prevent reclaim sealer from being recirculated into the source of virgin sealer.

Description:
BACKGROUND 
     This specification relates, in general, to vehicle sealer application systems. 
     Flowable sealer material is applied to various locations in a vehicle body during vehicle assembly such as to panel and to seal gaps between welded or fastened panels. The sealer is a flowable material applied by robot applicators or by operator manipulated applicators. 
     Excess applied sealer is removed for quality purposes by manual scraping. The excess sealer is stored in barrels and then disposed of following toxic material disposal procedures. 
     The excess sealer constitutes a hazardous waste and thereby poses hazardous waste generation and disposal issues. In addition, the cost of the excess waste sealer is lost money affecting the overall cost of manufacturing the vehicle. 
     There is a need to provide a method for recycling the excess sealer which reduces hazardous waste generation and provides a significant sealer material cost savings. 
     SUMMARY 
     An apparatus for supplying virgin sealing material and reclaim sealing material through a supply path to an applicator is disclosed. 
     The apparatus for applying sealing material through an applicator to a surface includes a source of virgin applied material sealer, a closed loop fluid flow pathway for supplying virgin material to the applicator and an excess recirculation path from the applicator to the source of virgin sealer. A first valve is positioned in the closed loop pathway to block the virgin sealer flow through a first portion of the closed loop pathway. A second valve is coupled in the closed loop pathway to control the flow of sealer through the recirculation path back to the source of virgin sealer. A source of reclaim sealer is coupled to a multi input node or the connection disposed in fluid flow communication with the closed loop pathway. A third valve is disposed in the supply path between the source of reclaim sealer and the node for controlling the flow of reclaim sealer to the node. A control controls the first valve, the second valve, and the third valve to selectively supply virgin sealer and reclaim sealer to the applicator while blocking recirculation of the reclaim sealer through the recirculation path to the source of virgin sealer. 
     The control operates to open the first valve, to open the second valve and to close the third valve to supply virgin sealer from the source of virgin sealer through the closed loop pathway, through the node to the applicator and then through the second valve and the recirculation path back to the source of virgin sealer. 
     The control operates to close the first valve, close the second valve and open the third valve to supply reclaim sealer from the source of reclaim sealer through the node and a first flow path portion of the close loop pathway to the applicator. 
     The control operates, after closing the third valve and opening the first valve, to maintain the second valve closed until all of the reclaim sealer in the first fluid flow path of the closed loop path is discharged through the applicator. 
     A method of supplying virgin sealer and reclaim sealer to a vehicle body includes providing a virgin sealer fluid flow loop to an applicator including a first fluid flow path from a source of virgin material to the applicator and a recirculation path of virgin sealer from the applicator back to the source of virgin sealer, supplying reclaim sealer from a source of reclaim sealer through a portion of the first fluid flow path to the applicator, while blocking the recirculation flow path from recirculating reclaim sealer. 
     The method includes coupling a first valve between the source of virgin sealer in the first fluid flow loop, coupling a second valve in fluid flow communication between the applicator, the first fluid flow loop and the recirculation path, coupling a third valve in fluid flow communication between the source of reclaim sealer and the first fluid flow loop. 
     The method includes controlling the opening and closing of the first valve, the second valve, and the third valve by opening the first valve and the second valve to allow flow of virgin sealer for the source of virgin sealer in the first fluid flow path to the applicator and back through the recirculation path to the source or virgin sealer while blocking flow or reclaim sealer through the portion of the first fluid flow loop. 
     The control also controls the opening and closing of the first valve, the second valve, and the third valve to allow flow of reclaim sealer to a portion of the first fluid flow loop to the applicator while blocking flow of reclaim sealer through the recirculation path. 
     The control closing the third valve to block flow of reclaim sealer into the first fluid flow loop, opening the first valve to allow flow of virgin sealer through the first fluid flow loop, and maintaining the third valve in a closed position blocking flow through the recirculation path until the first fluid flow path is clear of reclaim sealer. 
     The supply of virgin sealer when flowing through the first fluid flow loop forces the reclaim sealer through the first fluid flow loop to the applicator. 
     The method also couples at least one filter in a reclaim sealer supply path between the source of reclaim sealer and the connection to the first fluid flow path. 
     The method includes applying virgin sealer and reclaim sealer applied to a vehicle body by a robotic controlled applicator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The various features, advantages, and other uses of the present reclaim sealer application apparatus and method will become more apparent by referring to the following detailed description and drawing in which: 
         FIG. 1  is a pictorial representation of a vehicle sealer application system employing a reclaim sealer system and showing the virgin sealer and reclaim sealer systems in a virgin sealer application mode, 
         FIG. 2  is a pictorial representation, similar to  FIG. 1 , but showing the virgin sealer and reclaim sealer systems in a reclaim sealer application mode, 
         FIG. 3  is a schematic diagram of controller for controlling the sealer application apparatus shown in  FIGS. 1 and 2 , and 
         FIG. 4  is a perspective view of a reclaim sealer barrel change-out apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to to the drawing, and to  FIGS. 1-3  in particular, there is depicted a vehicle virgin and reclaim sealer application apparatus  8  and method. 
     Flowable sealer material is applied to various locations in a vehicle body  10  during vehicle assembly by a manual applicator, not shown, and/or by a robotic controller applicator  12 .  FIGS. 1 and 2  depict a robotic sealer applicator  12 , hereafter “applicator  12 ,” located on one side of the vehicle body  10 . It will be understood, that a vehicle assembly operation can have a pair of robotic sealer applicators  12  located on opposite sides of the vehicle body  10  for applying sealer material to the similar locations on opposite sides of the vehicle body, such as rocker seams, floor seams, door seams, etc. 
     By way of example only, the sealer application apparatus  8  includes a source  20  of virgin sealer  14 . The virgin sealer source  20  will typically include a refillable tank  22  having an inlet  24  and an outlet  26 . A pump  28  is coupled in fluid communication with fluid flow lines or conduits coupled to the tank outlet  26  for discharging virgin sealer  14  from the tank  22  to the applicator  12 . 
     The virgin sealer applicator apparatus  8  includes a closed loop flow path formed of conduits or pipe extending from the outlet  26  of the tank  22  through the pump  28 , a first supply line  30 , a first controllable valve  32  for opening and closing fluid flow from the first supply line  30  to a second supply line  34 , a node or tee connector  60  in the first supply line  30 , a mastic regulator  36 , a third supply line  38  extending from the mastic regulator  36  to a pump  40 , which may be a gear pump, a fourth supply line  42  extending from the pump  40  to a two position controllable second valve  44  and finally to a fifth supply line  46  extending from the second valve  44  to an actuator  48  on the robot applicator  12 . The closed loop flow path also includes a sixth supply line  50  hereafter referred to as a recirculation line extending in fluid flow communication between the second valve  44  and the inlet  24  of the tank  22 . 
     The closed loop pathway includes a first fluid flow path including the tee connection  60 , the second supply line  34 , the third supply line  38 , the fourth supply line  42  and the fifth supply line  46 , defined between the first valve  32 , the second valve  44  and the third valve  62 . 
     In operation, with the first and second valves  32  and  44  disposed in an open fluid flow position, virgin sealer  14  is discharged from the tank  22  by the pump  28  through the first and second supply lines  30  and  34 , the mastic regulator  36 , the third supply line  38 , the pump  40 , the fourth supply line  42 , through the second valve  44  and the fifth supply line  46  to the applicator  48 . Excess sealer is recirculated through the second valve  44  and the sixth supply line  50  back to the tank or source of virgin sealer material  22 . Also shown in  FIG. 1 , a heat exchanger  54  is disposed in heat transfer relationship with the second supply line  34  for controlling the temperature of the sealer flowing through the closed pathway loop. 
     The stippled symbols in the closed loop pathway depict virgin sealer flowing through the closed loop path in a first mode of sealer application to the vehicle body  10 . 
     A reclaim sealer supply loop is coupled in fluid flow communication with the first fluid flow via a node or tee connection  60  between short length supply lines disposed in fluid flow communication with the first valve  32  and a third valve  62 . 
     The reclaim sealer apparatus includes a barrel or container  70  containing reclaim sealer which is mountable in a stand  72 , described in greater detail with reference to  FIG. 4 , a pump  74  and a supply line or conduit  76  extending from an outlet  78  through first and second replaceable filters  80  and  82  to the third valve  62 . 
     The reclaim sealer apparatus also includes a level switch, such as proximity switch  88 , mounted on the stand  72  for detecting the level of reclaim sealer in the barrel  70 . A push button or other input actuator  90  is also provided in the reclaim sealer supply loop for initiating the flow of reclaim sealer from the the reclaim sealer barrel  70  to the robotic controlled actuator  48  as described hereafter. 
     As shown in  FIG. 3 , control  100 , such as a programmable logic controller (PLC), is provided for controlling the virgin sealer supply loop and the reclaim sealer supply loop and interfaces with a robot controller for the robot  12 . Inputs to the control  100  include the reclaim tank level switch  88  and the reclaim mode actuator push button  90 . 
     Outputs controlled by the controller  100  include the first virgin sealer pump  28 , the second reclaim sealer pump  74 , the first valve  32 , the second valve  44  and the third valve  62 . 
     Operation of the sealer apparatus  8  and method will start with application of virgin sealer to the vehicle body  10 . As shown in  FIG. 1 , the pump  28  is actuated by the control  100  to discharge virgin sealer  14  from the tank  22 . The control  100  opens the first valve  32  and the second valve  44  to allow the pump  28  to force virgin sealer  14  through the first and second supply lines  30  and  32 , through the mastic regulator  36 , the third supply line  38  and to the gear pump  40 . The pump  40  pumps the virgin sealer through the fourth supply line  42 , the fifth supply line  46  to the robot controlled applicator  48  where the virgin sealer  14  is applied to selected locations on the vehicle body  10 . Any excess virgin sealer  14  in the closed loop pathway is recirculated in the recirculation supply line  50  through the second valve  44  back to the tank  22 . As noted above, the stippling in  FIG. 1  shows the virgin  14  sealer in the closed loop supply  10 . 
     When it is desired to use the reclaim sealer in the barrel  70 , an operator depresses the push button  90  which, as an input to the control  100 , causes the control  100 , when executing a stored control program, to open the third valve  62  and close the first valve  32  and the second valve  44 . Closure of the second valve  44  closes the recirculation supply line  50  thereby blocking reclaim sealer from flowing through the second valve  44  and the recirculation supply line  50  back to the virgin sealer tank  22 . When the reclaim sealer pump  74  is activated by the control  100 , the pump  74  causes reclaim sealer to flow from the barrel  70  through the supply line  76 , through the filters  80  and  82  which may have different mesh filter sizes, such as  60  mesh for the first filter  40  in line and a smaller  60  mesh in the second filter  82 . The cross hatching shown in  FIG. 2  depicts the reclaim sealer flowing through the supply line  76 , the third valve  62 , through the connection  60  into a portion of the first fluid flow path including the second supply line  34 , the mastic regulator  36 , the third supply line  38 , the pump  40 , the fourth supply line  42  and the fifth supply line  46  to the applicator  48  which discharges reclaim sealer denoted by reference number  110  onto selected locations on the vehicle body  10 . Since the second valve  44  is closed to fluid flow, the reclaim sealer cannot enter the recirculation supply line  50  and is thereby prevented from contaminating the virgin sealer source tank  22 . It will be noted that there will be a transition period whereby the sealer application apparatus changes over from virgin sealer to reclaim sealer and back to virgin sealer. At the start of the transition period, as shown in  FIG. 1 , the controller  100  closes the first valve  32 , and the second valve  44 , while opening the third valve  62 . However, the tee connection  60 , the first supply line  34 , the second supply line  38 , the pump  40 , the third supply line  42 , the fourth supply line  46 , the fifth supply line  46  as well as the applicator  48  will be filled with virgin sealer. The flow of reclaim sealer through the supply line  76  to the tee connection  60  will then force the remaining virgin sealer in the first fluid flow path out through the applicator  48  onto vehicle body  10  until all of the virgin sealer has been discharged from the first fluid flow path and only reclaim sealer  48  remains in the first supply line  34 , the second supply line  38 , the third supply line  42 , the fourth supply line  46 , the fifth supply line  46 , and the applicator  48  as shown in  FIG. 2 . 
     A similar transition occurs when the level switch  88  detects that the level of reclaim sealer  70  has reached a low level. At this time, the control  100  closes the third valve  62  and opens the first and second valves  32  and  44 . However, the first, second, third, fourth and fifth supply lines  30 ,  34 ,  38 ,  42 , and  46  as well as the applicator  48  still contain reclaim sealer, as shown in  FIG. 2 . Subsequently, the virgin sealer flowing through the first valve  32  and tee connection  60  will force the reclaim sealer remaining in the supply lines out on onto the vehicle body until all of the reclaim sealer shown in  FIG. 2  has been discharged from the first fluid flow path leaving only virgin sealer in the supply lines as shown in  FIG. 1 . 
     Referring now to  FIG. 4 , there is depicted a changeover apparatus  120  for simplifying the changeover of the barrel  70  of reclaim sealer when the one barrel  70  is exhausted of reclaim sealer with a new barrel  71  filled with reclaim sealer. 
     As shown in  FIG. 4 , the stand  72  includes a pair of vertically extending legs  73  mounted on opposite sides of a frame  122 . The frame  122  includes a plurality of parallel rollers  124  which simplify the movement and exchange of an empty barrel  70  of reclaim sealer with a new full barrel  71  of reclaim sealer. During the barrel changeover, the fluid connections from the pump  74 , the air pressure line  126 , etc., are disconnected from the barrel  70  and the barrel  70  is slid along the rollers  124  out of the stand  72 . The new barrel  71  is then rolled into the stand  72  and connected to the pump  74  and the regulated airline  126  as well as other fluid connections necessary to pump reclaim sealer from the barrel  71  to the discharge line  76 .