Air blowing tool for heat-shrinkable packing material

Abstract

An air blowing tool includes a connecting pipe ( 1 ) and an air blowing head ( 2 ). The air blowing head includes an inner wall ( 22 ), and an outer wall ( 21 ). An annular passage ( 24 ) is defined between the inner and outer walls. The inner wall encloses and defines a heating space ( 23 ) for accommodating a package ( 3 ) to be heated. A plurality of evenly distributed outlets ( 221 ) is defined in the inner wall. Each outlet is defined at an acute angle relative to the annular passage. Each outlet is progressively flared such that a cross-sectional area of the outlet at the heating space is greater than a cross-sectional area of the outlet at the annular passage.

1 . A tool for blowing hot air onto heat-shrinkable packing material, the tool comprising: 
 a connecting pipe adapted to be connected with a hot air blower; and    an annular air blowing head comprising an outer wall, an inner wall, and an annular passage defined between the outer and inner walls and communicating with the connecting pipe, a circular heating space being defined inwardly from the inner wall and adapted for receiving a package having heat-shrinkable packing material, the head further comprising a plurality of outlets defined in the inner wall, each outlet communicating with the annular passage and with the heating space; wherein 
 each outlet is defined at an acute angle relative to the annular passage of the head such that a direction of air flow in the outlet is generally in compatible alignment with a direction of circulating air flow within the annular passage; and  
 each outlet is progressively flared such that a cross-sectional area of the outlet at the heating space is greater than a cross-sectional area of the outlet at the annular passage.  
   
     
     
         2 . The tool as described in  claim 1 , wherein each outlet has a generally arcuate configuration.  
     
     
         3 . The tool as described in  claim 1 , wherein the outlets are evenly distributed around the inner wall of the head.  
     
     
         4 . The tool as described in  claim 3 , wherein there are eight outlets.  
     
     
         5 . The tool as described in  claim 1 , wherein the connecting pipe includes a first pipe and a second pipe, the first pipe has a first passage, the second pipe has a second passage, a diameter of the second passage is less than a diameter of the first passage, and the annular passage of the head communicates with the second passage.  
     
     
         6 . The tool as described in  claim 5 , wherein the second passage communicates with the annular passage at an acute angle.  
     
     
         7 . A hot air blowing tool, comprising: 
 a pipe adapted for receiving hot air flow; and    an air blowing head integrally formed with the pipe, the head comprising an outer wall, an inner wall and an air passage defined between the outer and inner walls and in communication with the pipe, a plurality of outlets being defined in the inner wall, each outlet communicating with the air passage and a space surrounded by the inner wall.    
     
     
         8 . The tool as described in  claim 7 , wherein the head has an annular configuration, the air passage is annular, and each outlet is oriented at an acute angle relative to a direction of air flow within the air passage.  
     
     
         9 . The tool as described in  claim 8 , wherein each outlet has an arcuate configuration, and is oriented in compatible alignment with the direction of air flow within the air passage.  
     
     
         10 . The tool as described in  claim 9 , wherein each outlet is progressively flared such that a cross-sectional area of the outlet at the space surrounded by the inner wall is greater than a cross-sectional area of the outlet at the air passage.  
     
     
         11 . The tool as described in  claim 10 , wherein the pipe has a large passage and a small passage, and the small passage communicates with the air passage of the head.  
     
     
         12 . The tool as described in  claim 7 , wherein there are eight outlets.  
     
     
         13 . In combination, 
 a tool comprising: 
 a connecting pipe adapted to be connected with a hot air blower; and an annular air blowing head comprising an outer wall, an inner wall, and an annular passage defined between the outer and inner walls and communicating with the connecting pipe, a circular heating space being defined inwardly from the inner wall, the head further comprising a plurality of outlets defined in the inner wall, each outlet communicating with the annular passage and with the heating space;  
 a package having heat-shrinkable packing material and located around a center of the space; wherein  
 each outlet is progressively flared such that a cross-sectional area of the outlet at the heating space is greater than a cross-sectional area of the outlet at the annular passage.  
   
     
     
         14 . The combination as described in  claim 13 , wherein each outlet is defined at an acute angle relative to the annular passage of the head such that a direction of air flow in the outlet is generally compatible with a direction of circulating air flow within the annular passage to guidably attract the circulating air flow into the outlet and result in turbulence in the space.  
     
     
         15 . The combination as described in  claim 14 , wherein the direction of the air flow in the outlet is not radially directed toward a center of the space.