Integral pipe and fitting assembly of polymer material, and method of making same

Abstract

A hose and fitting assembly comprising a hose of a first thermoplastic polymer material having an end portion ( 9 ) with an inner surface ( 8 ) and an outer surface ( 15 ) and a fitting ( 3 ) of a second polymer material for connection with an external point of use. The fitting ( 3 ) has a central tubular projection ( 4 ) with an axial fluid passageway ( 6 ). The central tubular projection ( 4 ) has an inner wall ( 5 ) which defines the fluid passageway ( 6 ) and an outer wall ( 7 ), at least partly integrally coupled to the inner surface ( 8 ) of the end portion ( 9 ) of the hose ( 2 ). The hose and fitting assembly comprises reinforcement means ( 11 ) of a third polymer material at the periphery of the end portion ( 9 ) of the hose ( 2 ) for restraining radial deformations of the hose and providing the assembly with a good mechanical and/or hydraulic sealing capability. A method of making such assembly.

1 . A hose/fitting assembly comprising:
 a hose ( 2 ) of a first thermoplastic polymer material having an end portion ( 9 ) with an inner surface ( 8 ) and an outer surface ( 15 ),   a fitting ( 3 ) of a second polymer material for connection with an external point of use, said fitting ( 3 ) having a central tubular projection ( 4 ) with an axial fluid passageway ( 6 ),   
     wherein said central tubular projection ( 4 ) has an inner wall ( 5 ) which defines said fluid passageway ( 6 ) and an outer wall ( 7 ), at least partly integrally coupled to the inner surface ( 8 ) of said end portion ( 9 ) of said pipe ( 2 ),
 characterized by comprising reinforcement means ( 11 ) of a third polymer material at the periphery of said end portion ( 9 ) of said hose ( 2 ) for restraining radial deformations of the hose and providing the assembly with a good mechanical and/or hydraulic sealing capability. 
 
   
   
       2 . Assembly as claimed in  claim 1 , characterized in that said reinforcement means ( 11 ) include an annular member ( 12 ), having an outer face ( 13 ) and an inner face ( 14 ) designed to be coupled to said outer surface ( 15 ) of said end portion ( 9 ) of said hose ( 2 ). 
   
   
       3 . Assembly as claimed in  claim 2 , characterized in that said outer surface ( 15 ) of said end portion ( 9 ) of said hose ( 2 ) is at least partly integrally coupled to said inner face ( 14 ) of said annular member ( 12 ). 
   
   
       4 . Assembly as claimed in  claim 2 , characterized in that said annular member ( 12 ) is integral with said fitting ( 3 ). 
   
   
       5 . Assembly as claimed in  claim 4 , characterized in that said annular member ( 12 ) integral with said fitting ( 3 ) is coaxial with said central tubular projection ( 4 ) and radially spaced therefrom to define an interspace ( 16 ) having a bottom wall ( 17 ) and an opening ( 18 ), designed to receive said end portion ( 9 ) of said hose ( 2 ). 
   
   
       6 . Assembly as claimed in  claim 5 , characterized in that said end portion ( 9 ) of said hose ( 2 ) is at least partly integrally coupled to the bottom wall ( 17 ) of said interspace ( 16 ). 
   
   
       7 . Assembly as claimed in  claim 1 , characterized in that said reinforcement means ( 11 ) further include an expanded area ( 21 ) of said end portion ( 9 ) of said hose ( 2 ). 
   
   
       8 . Assembly as claimed in  claim 7 , characterized in that said expanded area ( 21 ) is at least partly defined by two or more at least partly overlapping hose sections ( 22 ,  22 ′). 
   
   
       9 . Assembly as claimed in  claim 1 , characterized in that said outer wall ( 7 ) of said tubular projection ( 4 ) is inwardly tapered for easier connection with the inner surface ( 8 ) of said end portion ( 9 ) of said hose ( 2 ). 
   
   
       10 . Assembly as claimed in  claim 2 , characterized in that said inner face ( 14 ) of said annular member ( 12 ) is outwardly tapered for easier connection with said outer surface ( 15 ) of said end portion ( 9 ) of said hose ( 2 ). 
   
   
       11 . Assembly as claimed in  claim 1 , characterized in that said first polymer material is compatible with said second polymer material and/or said third polymer material. 
   
   
       12 . Assembly as claimed in  claim 1 , characterized in that said second polymer material and/or said third polymer material are stiffer than said first polymer material. 
   
   
       13 . Assembly as claimed in  claim 1 , characterized in that said first polymer material is of the same nature as said second polymer material and/or said third polymer material. 
   
   
       14 . Assembly as claimed in  claim 1 , characterized in that said first polymer material and/or said second polymer material and/or said third polymer material are selected from the group comprising PVC, PU, EVA, PE, PP, PBT, PET, PA, PMMA, natural or synthetic rubbers or a combination thereof. 
   
   
       15 . Assembly as claimed in  claim 14 , characterized in that said first polymer material and/or said second polymer material and/or said third polymer material are of the homopolymer or copolymer type. 
   
   
       16 . Assembly as claimed in  claim 1 , characterized in that said third polymer material is identical to said second polymer material. 
   
   
       17 . Assembly as claimed in  claim 1 , characterized in that the ratio between the length (L A ) of said tubular projection ( 4 ) and the inside diameter (D I ) of said hose ( 2 ) is in a range from about 0.5 to about 8, and preferably of nearly 2. 
   
   
       18 . Assembly as claimed in  claim 2 , characterized in that the ratio between the length (L B ) of said annular member ( 12 ) and the inside diameter (D I ) of said hose ( 2 ) is in a range from about 1 to about 12, and preferably of nearly 4. 
   
   
       19 . Assembly as claimed in  claim 2 , characterized in that the ratio between the length (L B ) of said annular member ( 12 ) and the length (L A ) of said tubular projection ( 4 ) is in a range from about 1 to about 4, and preferably of nearly 2. 
   
   
       20 . Assembly as claimed in  claim 1 , characterizsed in that said reinforcement means ( 11 ) further include a fibrous reinforcement layer ( 24 ) in said hose ( 2 ) between said at least one outer protective layer ( 25 ) and at least one inner layer ( 26 ) designed to contact the fluid to be carried. 
   
   
       21 . Assembly as claimed in  claim 20 , characterized in that said fibrous reinforcement layer ( 24 ) has a braided, spiral wrapped, knitted, taped or mesh form with simple or double chain stitches. 
   
   
       22 . Assembly as claimed in  claim 21 , characterized in that said chain-mesh fibrous layer ( 24 ) has substantially parallel lines of stitches ( 27 ) and/or substantially parallel rows of stitches ( 29 ). 
   
   
       23 . Assembly as claimed in  claim 22 , characterized in that said lines of stitches ( 27 ) and said rows of stitches ( 29 ) are mutually inclined with respect to the longitudinal axis (Y) of the hose ( 2 ), at respective predetermined angles (α, β). 
   
   
       24 . A method of making a hose/fitting assembly as claimed in  claim 1 , characterized in that it comprises the steps of:
 providing a hose ( 2 ) of a first thermoplastic polymer material having an end portion ( 9 ) with an inner surface ( 8 ) and an outer surface ( 15 );   providing a fitting ( 3 ) of a second polymer material for connection with an external point of use, said fitting having a central tubular projection ( 4 ) with an axial fluid passageway ( 6 );   
     wherein said central tubular projection ( 4 ) has an inner wall ( 5 ) which defines said fluid passageway ( 6 ) and an outer wall ( 7 ), to be coupled to the inner surface ( 8 ) of said end portion ( 9 ) of said pipe ( 2 );
 fixing said fitting ( 3 ) to said hose ( 2 ) by at least partial integral coupling of said outer wall ( 7 ) of said tubular projection ( 4 ) to said inner surface ( 8 ) of said end portion ( 9 ) of said hose ( 2 ); 
 providing reinforcement means ( 11 ) of a third polymer material to be placed at the periphery of said end portion ( 9 ) of said hose ( 2 ); 
 placing said reinforcement means ( 11 ) at the periphery of said end portion ( 9 ) of said hose ( 2 ) to restrain radial deformations of the hose and ensure integrity of the assembly. 
 
   
   
       25 . Method as claimed in  claim 24 , characterized in that said integral coupling step is carried out by rotational friction welding.