Abstract:
The machine is an index spraying machine. The machine has five different stations. The first station is the load/unload station. At this station, work pieces are unloaded after they have been sprayed and new work pieces to be sprayed are loaded on. New pieces then move into the pre-heat station tunnel. A third station is the spraying area. In this area, the work pieces are sprayed. After being sprayed, the work pieces move in the area where they are heated to flash off the volatile fumes. Then they move to the fifth work station where they are cooled and finally they move back into the load/unload station. The spraying area in this machine is sealed to meet NEMA 7 standards. The air capture system cascades the air, thus lowering the air volume that passes through the thermal oxidizer.

Description:
FIELD OF INVENTION 
   This invention relates to the field of spraying machine and more particularly to a station index spray machine. 
   BACKGROUND OF INVENTION 
   The United States government has placed strict standards on the making of spray machines. These standards are known as NEMA 7 compliance. These standards basically state that no electrical wiring or connections be exposed to the volatile fumes. Thus, one of the objectives of this invention is to create a spray booth which meets NEMA 7 compliance and no volatile fumes that make any contact with any wiring or connections. The feature that meets this objective is that the spray booth is sealed and all electrical components remain outside the spray booth. The inventor knows of no other indexing spray machine that meets NEMA 7 compliance. Another objective of this invention is that even though none of the electrical components are contained within the spray booth, the inventor is still able to spray a complete range of patterns on the work piece. The feature that accomplishes this is that the inventor extends actuator arms with sprayer attachments down from the top of the spray booth, thus leaving electrical components above the spray booth, but the sprayer arms are fully sealed by sleeves so that none of the volatiles seep out of the spray booth and into the area of the electrical components. These actuator arms move the sprayer up and down. The spindles holding the work piece also rotate and, thus, the spray gun can spray the workpiece in a complete assortment of different patterns. 
   Another feature much sought after in the art is to create an air capture system that efficiently removes the volatile fumes; however, sends only a small volume of air so that one is not sending large volumes of air through the oxidizer. The oxidizer burns the volatile fumes and by lowering the amount of air sent through the oxidizer, reduces the size of the oxidizer and the cost of operation. The feature used by the inventor to achieve this objective is he cascades the air to produce a small volume of air going to the oxidizer. 
   SUMMARY OF THE INVENTION 
   The machine is an index spraying machine. The machine has five different stations. The first station is the load/unload station. At this station, work pieces are unloaded after they have been sprayed and new work pieces to be sprayed are loaded on. New pieces then move into the pre-heat station tunnel. A third station is the spraying area. In this area, the work pieces are sprayed. After being sprayed, the work pieces move in the area where they are heated to flash off the volatile fumes. Then they move to the fifth work station where they are cooled and finally they move back into the load/unload station. The spraying area in this machine is sealed to meet NEMA 7 standards. The air capture system cascades the air, thus lowering the air volume that passes through the thermal oxidizer. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a front view of the load/unload station. 
       FIG. 2  is a view of the preheat zone air system. 
       FIG. 3  is a view of the spray booth with the doors closed and showing the upper workings of the actuator arms and the DC actuators. 
       FIG. 3A  shows the spray booth with the doors removed showing the seal around the door area. 
       FIG. 4  shows the inside of the spray booth. 
       FIG. 5  shows the base frame. 
       FIG. 5A  is a view of the drive mechanism of the table. 
       FIG. 6  shows the base frame enclosed with the table in place. 
       FIG. 7  is a view of the safety gate when open. 
       FIG. 8  is a view of the duct work of the air capture system. 
       FIG. 9  is a view of the control panel. 
       FIG. 10  is a view of the electric panel enclosure. 
       FIG. 11  is a view of the thermal oxidizer. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The machine has basically five different stations. The load-unload station  10  is where the process begins. At this station, the work piece  12  is placed on a spindle  14 .  FIG. 1  shows the load-unload station  10 . In the preferred embodiment, the work piece  12  is placed on a spindle  14  by an operator. However, the work pieces  12  could be placed on automatically. In the preferred embodiment, the machine indexes to the left and indexes two spindles  14  at a time. 
   The next station the machine indexes with the work piece  12  on the spindle  14  is the pre-heat zone tunnel  16 . In the pre-heat zone tunnel  16 , the spindle  14  begins to rotate and rotates through the rest of the process until it indexes into the load-unload station  10 . The rotation speed of the spindle  14  is governed by an “AC” controlled variable speed and is adjustable according to product requirements. The operator at the load-unload station  10  can control this speed from his control panel  20 . The same rotation speed is maintained throughout the whole process of indexing around the machine until the spindle  14  actually arrives back at the load-unload station  10 . The spindle  14  does not spin at the load-unload station  10 . The pre-heat zone tunnel  16 , contains heated air that is continually re-circulated through a close-loop system shown in  FIG. 2 . This air can be re-circulated since there are no volatile chemicals generated in the pre heat zone tunnel  16 . The rotating spindle  14  with the workpiece  12  remain in the heated environment through many index steps to bring the workpiece  12  to the desired temperature prior to their entering the spray booth zone  18 . As the table  22  continues to index, the rotating spindles  14  and workpiece  12  emerge from the pre-heated zone tunnel  16  and enters the spray booth zone  18 . There are two spray booths zones  18  and  24  shown in  FIG. 3  in the preferred embodiment. However, this number can be more or less. As the workpiece  12  indexes from the pre-heat zone tunnel  16  into the spray booth zone  18 , it moves through a set of nylon bristles  34  as shown in  FIGS. 3 and 4 . These nylon bristles  34  are there to prevent volatile fumes in the air of the spray booth zone  18  entering into the air of the pre-heat zone tunnel  16 . Once the rotating spindles  14  and the workpiece  12  enter the first spray booth zone  18 . The awaiting spray guns  26  shown in  FIG. 4  will receive a signal to begin spraying the pre-heated workpiece  12  with the appropriate substance and in the predetermined pattern. Since the preferred embodiment has two spray booth zones  18  and  24 , this substance would probably be some type of primer. However, any sprayable substance can be used. The spray booth handles two spindles  14  and workpieces  12  at a time, and there are two different spray guns  26 , one for each spindle  14 . Both spray guns  26  can spray the inner diameter and/or the outer diameter of the work piece  12 . The spray booth zones  18  and  24  takes two spindles  14  at a time and has two spray guns  26  and, thus, probably will be spraying two workpieces  12  at a time. However, when the size of the workpiece  12  side exceeds the spindle  14  spacing, it will be necessary only to have one workpiece  12  placed on every other spindle  14 . Thus, the first spray booth zone  18  would only spray one part at a time. The dc-controlled actuators  28  come down from above as shown in  FIG. 3 . The dc-controlled actuators  28  drive the spray guns  26  vertically at a pre-determined feed rate. The spray gun  26  and the de-controlled actuators  28  are designed so that the spray guns  26  can spray the inner or outer diameter of most workpieces  12  and can spray in almost any desired pattern upon said workpiece  12 . With the next indexing, the workpiece  12  moves to the next set of spray guns  26  where another coating is placed upon this workpiece  12 . 
   Upon completing the spraying of the workpiece  12  the workpiece  12  is indexed into the cure zone tunnel  30  of the machine. The completely sprayed workpiece  12  will remain in the cure zone tunnel  30  through several indexes. The cure zone tunnel  30  contains heated air that will be at a temperature to facilitate the “flash off” of solvent from the spray that was applied. This process is known as curing. In the preferred embodiment, the sprayed workpiece  12  continues to advance clockwise through it&#39;s indexing and through the cure zone tunnel  30 . The workpiece  12  exits the cure zone tunnel  30  into the “cool” zone tunnel  32 . At this point in the process, cooler “ambient” air will be blown directly on the sprayed and cured workpiece  12  to remove heat from the part for the handling by the operator at the load-unload station  10 . The workpiece  12  will continue through the cool zone  32  until it is reduced to safe handling temperature and then it will index into the load-unload station  10  to be unloaded. 
   The air capture system  50  shown in  FIG. 8  begins at the load-unload station  10  with the ambient air being pulled through the load-unload air diverter  82  shown in  FIGS. 1 and 8  located directly in front of the operator. The air will pass through the intake filter  72  removing any dirt and debris prior to entering the overall air capture system  50 . The air is pulled through with a first blower  54  and once the first blower  54  pulls the air through the intake filter  72 , the air is exhausted from the discharge and is diverted in two directions. Dampers  56  are used to control the air flow. The air flow is directed in two directions. Some of the air flow is first diverted directly downward through a cool zone duct  46  into cooling zone tunnel  32  to cool the cured workpiece  12  prior to the load-unload station  10 . The rest of the remaining air is directed further down stream towards heater duct  44  and into a heater  58 . This heater  58  heats the air and then forces the air into the cure zone tunnel  30  through cure zone duct  42 . This heated air is utilized in the flashing off process after the spraying of the volatiles. 
   The second portion of the air capture system  50  shown in  FIG. 8  is a second blower  64  that pulls the air out of the cool zone  32  and the cure zone tunnels  30  through collector duct  40 . The air is pulled out of the cool zone  32  and the cure zone tunnels  30 , and this air is then split off through Y duct  38  to both sides of the spray booth zones  18  and  24 . The air is put through two vertical air knives  66  and  68  shown in  FIG. 4 . One air knife  66  is located on the side of spray booth zone  18  near where the workpiece  12  enters the spray booth zone  18  from the pre-heat zone tunnel  16  and the other air knife  68  is located where the workpiece  12  leaves spray booth  24  to the cure zone tunnel  30 . The air is directed into the spray booth zones  18  and  24  via the vertical air knife  66  and  68  to facilitate the air flow into the spray booth air diverters  70  and away from the spray guns  26 . The spray booth zones  18  and  24  are where the majority of the volatile fumes will be generated. The air is then drawn up out of the spray booth zones  18  and  24  through spray booth air diverter  70  and into and through a one inch thick polyester filter  74  and into spray booth duct  98 . The air with the volatile fumes is then pulled through filter box  80 . There are two filters in filter box  80 . The first polyester filter in the preferred embodiment is 2 inches thick, and the second filter, the safety filter is 12 inches thick. These filters capture most of the solids in the air. The filtered air is then drawn into a second blower  64  which is controlled by a variable frequency drive. It is possible to control both blower  54  and  64  by a variable frequency drive. Thus, the amount of air pumped by blower  64  can be controlled. The second blower  64  pushes the air into the thermal oxidizer  150  which burns the volatile substances in the air. 
     FIG. 5 and 5A  shows the base frame  100  of the invention. In the center of the base frame  100  is the motor drive  102  for the table  22 . Motor  102  drives the table  22  shown in  FIG. 6 . In the preferred embodiment, the drive motor  102  is a Ferguson drive and the drive motor  102  is an AC variable speed motor. The drive motor  102  has an air clutch  106  and brake  108 . Base frame  100  is fully enclosed as shown in  FIG. 6 .  FIG. 6  also shows the table  22  with spindles  14 . Around the outer edge of the table  22  is a stainless steel brush  110 . This stainless steel brush  110  keeps the volatiles from seeping around the edge of the table  22  and down into the area with the motor drive  102 . To further ensure that there are no volatiles in this area, the air capture system  50  draws air from this area. A bottom center duct  115  from the air capture system  50  runs down through the opening  114  in the center of the table  22 , and this duct exhausts the air from underneath the table  22  and within the inner area of the base frame  100 . 
     FIG. 1  shows the load/unload station  10 . The load/unload station  10  has two ways in which the operator can, in the case of emergency, stop the indexing of the machine. First is the safety gate  116 . This safety gate  116  surrounds the entrance to the pre-heat zone tunnel  16 . 
     FIG. 7  shows the safety gate  116  partially removed. In this figure, you can see how this safety gate  116  works. An operator who wishes to stop the indexing of the machine, presses on the safety gate  116 . Beneath the safety gate  116  are springs  118  which hold it away from the entrance to the pre-heat zone tunnel  16 . There is also a stop pin  120  so that when an operator presses on the safety gate  116 , it compresses the springs  118  and makes contact with the stop pin  120  which stops the indexing of the machine. Also on the inside of the safety gate  116  is a workpiece sensor  122 . This sensor  122  has an electronic eye and checks to ensure that there is a workpiece  12  on the spindle  14 . If there is no workpiece  12  on the spindle  14 , the sensor  122  notifies the computer, and the computer does not activate the spray guns  26  for the spindle  14  without a workpiece  12 , and thus, no paint will be used. 
   Another safety device is the wire  124  shown in  FIG. 1  that runs at the top of the load/unload station  10 . If this wire  124  is pulled by the operator, the indexing of the machine stops. The wire  124  is attached to a sensor which notifies the electronic system to stop the indexing of the machine. Also, at the back of the load/unload booth is an air intake  82 , the main air intake, for the capture system  50 . The air is pulled through this air intake  82  into the air capture system  50 . There is a intake filter  72  on this air intake  82  to ensure that dirt and other objects do not contaminate the air going into the air capture system  50 . 
     FIG. 3  shows the spray booth zones  18  and  24 . On the outside of the spray booth zones  18  and  24  are two doors  128  that allows one to enter into the spray booth zones  18  and  24  and set up intrinsically safe different sensing devices within the booth to sense how well the spraying occurs or the temperature of the workpiece  12 . Thus, an individual could set up pyrometers within the spray booth zones  18  and  24  or other sensing devices. Each spray booth zones  18  and  24  has two spray guns  26  and two spindles  14 . In other words, the machine has four spray guns  26 . The doors  128  on the spray booth zones  18  and  24  are a rubber seal  130  around the circumference of the opening to the spray booth zones  18  and  24  which is shown in  FIG. 3A  and are pressure fastened so that no volatiles will escape out of the spray booth zones  18  and  24  when the doors  128  are closed. 
     FIG. 4  shows the inside of the spray booth zones  18  and  24 .  FIG. 4  shows that on the sides of the spray booth zones  18  and  24  are air knives  66  and  68 . This is where the air from the air capture system  50  enters the spray booth zones  18  and  24 . The air from the air capture system  50  enters through the air knives  66  and  68 . The air flow is diverted by these air knives  66  and  68  away from the spray guns  26  so that it does not affect the spraying of the paint. The air is withdrawn from the spray booth zones  18  and  24  through the air diverters  70  and through a one inch thick polyester filter and into a spray booth duct  98  in the back of the spray booth zones  18  and  24 . The air is pulled through a Dynacom filter box  80  in which the first filter is two inches thick and the second filter is twelve inches thick. 
     FIG. 3  shows the area above the spray booths  18  and  24 . In this area is the dc controlled actuators  28  that move the spray guns  26  shown in  FIG. 4 . A floor  138  separates the dc controlled actuators  28  from the spray booths  18  and  24 . Only the control rods  140  extend down from the dc controlled actuators  28  through the floor  138  and into the spray booths  18  and  24 . The spray guns  26  are attached to the control rods  140 . As we can see from  FIG. 3 , the control rods  140  extend through the floor  138 ; however, the control rods  140  are covered by sleeves  142  that attach to the bottom of a floor  138  and the control rod  140  and completely seal the spray booth zones  18  and  24  so no volatiles can escape through the openings for the control rods  140 . The sleeves  142  are expandable so that the control rods  140  can move up and down and can move the spray gun  26  vertically. In the preferred embodiment, the dc controlled actuators  28  from the above drive the spray guns  26  vertically at a predetermined rate. 
   At the load/unload station  10  is a control panel  20  shown in  FIG. 9 . From the control panel  20 , the operator can control all aspects of the machine. He can control the speed at which the machine indexes, the temperature of pre-heat zone tunnel  16  and the cure zone tunnel  30 , the rate at which spray guns  26  dispense their liquid, the vertical movement of the spray guns  26 , rate at which the spindles rotate  14 , and all the other aspects of the machine. Also, the system can be designed so that for a given part number, the machine will automatically know the spray pattern for the spray guns  26 . 
     FIG. 10  shows the electric panel enclosure  144 . Within this enclosure is contained all the controls for the electrical system including the micro processor that controls the whole system. 
     FIGS. 2 and 8  show the duct work on the top of the machine. This duct work contains the blowers  54 ,  64 ,  152 , and duct work of the air capture system  50 . The duct work of the air capture system  50  begins at the load/unload station  10  where the outside air is being pulled through an air intake  82  located directly in front of the operator as shown in  FIG. 1 . The air passes through the intake filter  72  which removes any dirt and debris prior to entering the overall air capture system  50 . The air is pulled up from load/unload station  10  air intake  82  through first duct  86 . The air is pulled by the first blower  54 . The first blower  54  feeds the air out into blower duct  88 . Along this blower duct is damper  56 . Dampers  56  controls the air flow into cool zone tunnel duct  46  and cure heater  58 . Air diverted into cool zone tunnel duct  46  flows into the cool zone tunnel  32 . The air diverted into heater  58  flows out of heater  58  into cure zone tunnel duct  42  and downward into the curing zone tunnel  30 . The air from both the curing zone tunnel  30  and the cooling zone tunnel  32 , then flows up through exhaust duct  40  into a Y fitting  38 . The air is then divided along the right and left channel ducts  146  and  148 . The air in right channel duct  146  flows into air knife  66  in the spray booth zones  18  and  24 , and the air from left channel duct  148  flows through air knife  68  into spray booth  24 . The air is pulled out of spray booth zones  18  and  24  through the spray booth exhaust duct  98  by blower  64 . Actually the air is pulled out of spray booth zones  18  and  24  through spray booth exhaust duct  98  and filter box  80  by blower  64 . The air is exhaled out of blower  64  to the thermal oxidizer  150  which incinerates the volatile fumes. 
     FIG. 2  shows the preheat zone air system. This system contains preheat zone blower  152  and preheat zone heater  154 . The pre heat zone blower  152  intakes the air from the preheat zone tunnel  16  through preheat zone heater  154 . The air is heated by the preheat zone heater  154  and returned to the preheat zone tunnel  16  by the preheat zone blower  152 . Thus this air is continually recirculated which lower the energy cost of heating this air. The preheat zone tunnel contains no volatile fumes and thus it is not necessary to have this air flow through the air capture system  50  or the thermal oxidizer  150 . 
   Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appending claims