Heated hose for carrying molten thermoplastic material

Abstract

A hose for transferring heated liquid, such as molten thermoplastic material. The hose includes a conduit that has an inlet end adapted to couple with a source of heated liquid, such as a heated supply tank, and a discharge end adapted to couple with a liquid dispensing apparatus, such as an applicator gun. In one embodiment, the hose may be covered by a woven outer sheath of polyamide that protects the underlying hose against abrasion damage. In another embodiment, the hose may include a hose cuff mechanically coupled with the liquid dispensing apparatus to bolster resistance to axial tensile forces and bending forces applied to the hose.

1 . An apparatus for transferring a heated liquid from a heated liquid source to a liquid dispensing apparatus, comprising: 
 a conduit having an inlet end adapted to be coupled in fluid communication with the heated liquid source and a discharge end adapted to be coupled in fluid communication with the liquid dispensing device;    a thermal insulation layer extending between said inlet end and said discharge end of said conduit;    a heating element extending between said inlet end and said discharge end of said conduit and positioned between said thermal insulation layer and said conduit, said heating element adapted to generate and transfer heat to said conduit; and    a woven outer covering extending between said inlet end and said discharge end of said hose and having a surrounding relationship with said hose, said woven outer covering including a plurality of braided polyamide monofilaments.    
   
   
       2 . The hose of  claim 1  wherein said woven outer covering includes a plurality of oval-shaped monofilaments.  
   
   
       3 . The hose of  claim 1  wherein said woven outer covering is formed from eighty monofilament carriers.  
   
   
       4 . The hose of  claim 1  wherein said woven outer covering has an outer surface free of undulating structures.  
   
   
       5 . The hose of  claim 1  further comprising: 
 a hose cuff attaching said woven outer covering to said discharge end of said hose, said hose cuff including at least one coupling element for securing said hose cuff to the liquid dispensing device and preventing relative axial movement between said hose cuff and the liquid dispensing device.    
   
   
       6 . An apparatus for transferring a heated liquid from a heated liquid source to a liquid dispensing device, comprising: 
 a conduit having an inlet end adapted to be coupled in fluid communication with the heated liquid source and a discharge end adapted to be coupled in fluid communication with the liquid dispensing device;    a thermal insulation layer extending between said inlet end and said discharge end of said conduit;    a heating element extending between said inlet end and said discharge end of said conduit and positioned between said thermal insulation layer and said conduit, said heating element adapted to generate and transfer heat to said conduit; and    a hose cuff attached to said discharge end of said hose, said hose cuff including at least one coupling element for directly securing said hose cuff to the liquid dispensing device and preventing relative axial movement between said hose cuff and the liquid dispensing device.    
   
   
       7 . The hose of  claim 6  wherein said hose cuff includes a sidewall, and said coupling element comprises a recess in said sidewall, said recess shaped to engage a complementary portion of the liquid dispensing device.  
   
   
       8 . The hose of  claim 7  wherein said sidewall is cylindrical, and said recess includes a major axis aligned substantially tangential to a circumference of said sidewall.  
   
   
       9 . The hose of  claim 6  wherein said hose cuff includes a sidewall and said coupling element comprises an opening extending through said sidewall, said opening shaped to engage a complementary portion of the liquid dispensing device.  
   
   
       10 . The hose of  claim 9  wherein said sidewall is cylindrical, and said opening includes a major axis aligned substantially tangential to a circumference of said sidewall.  
   
   
       11 . The hose of  claim 6  wherein said hose cuff includes a tubular body having a first open end, a second open end, and a collar covering said first open end, said tubular body is substantially centered about an axis extending between said first and second open ends, said collar includes a first opening, and said hose includes a first electrical lead projecting through said first opening.  
   
   
       12 . The hose of  claim 11  wherein said collar includes a second opening, and said hose includes a second electrical lead projecting through said second opening.  
   
   
       13 . The hose of  claim 12  wherein said collar includes a third opening substantially centered about said axis, and said hose includes a tube confining the heated liquid during transfer and projecting through said third opening, said first opening and said second opening being radially spaced from said third opening.  
   
   
       14 . The hose of  claim 13  wherein said first opening and said second opening are positioned on opposite sides of said third opening.  
   
   
       15 . A method of attaching a hose between a liquid source and a liquid dispensing device, comprising: 
 coupling a fitting at a discharge end of the hose with the liquid dispensing device; and    directly coupling a hose cuff at the discharge end of the hose with a portion of the liquid dispensing device for preventing relative axial movement between the hose cuff and the liquid dispensing device during use.    
   
   
       16 . The method of  claim 15  wherein directly coupling further comprises: 
 engaging the hose cuff with the liquid dispensing device.    
   
   
       17 . The method of  claim 15  wherein directly coupling further comprises: 
 engaging a groove on the hose cuff with a post inside a shell of the liquid dispensing device.