Heater in a conveyor system

Abstract

In a conveyor system with a radiant heating system, convection is provided with hollow elongated tubes having small holes for providing a gentle air flow toward a workpiece to heat the workpiece with convection and radiation.

What is claimed is:  
     
         1 . A liquid dispensing system for dispensing liquid on a circuit board comprising: 
 a conveyor for transporting the circuit board along a direction of travel to a working position;    a liquid dispenser mounted for dispensing liquid on the circuit board when the circuit board is in the working position;    a heater mounted under the conveyor when the circuit board is in the working position for heating the circuit board; and    a first elongated hollow tube mounted under the heater and having holes oriented so that when a gas is introduced into the first tube, the gas is directed upwardly through the holes, past the heater, and toward the circuit board.    
     
     
         2 . The system of  claim 1 , further comprising a second hollow tube mounted parallel to the first tube and having holes oriented to direct a gas through the holes upwardly past the heater and toward the circuit board.  
     
     
         3 . The system of  claim 2 , wherein the conveyor has first and second parallel rails elongated along a first direction, the rails being movable relative to each other in a second direction transverse to the first direction, the first and second tubes being coupled to move along the second direction with the rails.  
     
     
         4 . The system of  claim 3 , further comprising a third hollow tube mounted parallel with and between the first and second tubes.  
     
     
         5 . The system of  claim 4 , wherein the heater includes a plurality of elongated heating tubes mounted in parallel and extending transverse to the direction of travel.  
     
     
         6 . The system of  claim 5 , wherein the holes of the first tube are at locations halfway between pairs of adjacent heating tubes.  
     
     
         7 . The system of claims  1 , further comprising an air supply coupled to each end of the first tube for providing air at each end.  
     
     
         8 . The system of  claim 1 , wherein the first tube is made of black anodized aluminum.  
     
     
         9 . The system of  claim 1 , wherein the heater includes a plurality of heating tubes mounted in parallel and extending transverse to the direction of travel.  
     
     
         10 . The system of  claim 9 , wherein the holes of the first tube are at locations halfway between adjacent heating tubes.  
     
     
         11 . The system of  claim 1 , further comprising a second hollow tube, wherein the heater includes a plurality of elongated heating tubes mounted in parallel and extending transverse to the direction of travel.  
     
     
         12 . The system of  claim 11 , wherein the holes of the first tube are at locations halfway between pairs of adjacent heating tubes.  
     
     
         13 . A system for conveying and heating a workpiece comprising: 
 a conveyor for transporting the workpiece along a direction of travel;    a heater mounted on one side of the conveyor for heating the workpiece; and    a first hollow elongated tube mounted so that the heater is between the workpiece and the first tube, the first tube having a plurality of holes oriented so that when a gas is introduced into the first tube, the gas is directed through the holes, past the heater, and toward the workpiece.    
     
     
         14 . The system of  claim 13 , further comprising a second hollow tube mounted parallel to the first tube and having holes oriented so that when a gas is introduced into the second tube, the gas is directed upwardly through the holes in the second tube, past the heater, and toward the circuit board.  
     
     
         15 . The system of  claim 14 , wherein the conveyor has first and second parallel rails elongated along a first direction, the rails being movable relative to each other in a second direction transverse to the first direction, the first and second tubes being coupled to move along the second direction with the rails.  
     
     
         16 . The system of  claim 13 , further comprising an air supply coupled to each end of the tube.  
     
     
         17 . A system for heating a workpiece comprising: 
 a support for supporting the workpiece in a working position;    a heater mounted for heating one side of the workpiece; and    a first hollow elongated tube mounted so that the heater is between the workpiece and the first tube, the first tube having a plurality of holes oriented so that when a gas is introduced into the first tube, the gas is directed through the holes, past the heater, and toward the workpiece.    
     
     
         18 . The system of  claim 17 , wherein the heater includes a plurality of parallel heating tubes and the hollow elongated tube is transverse to the heating tubes.  
     
     
         19 . The system of  claim 18 , further comprising a second hollow elongated tube with holes, the second tube being mounted parallel to the first tube.