Flexible conduit for vehicle engine coolant circuits

A flexible conduit for connecting a coolant circuit of an engine to a radiator, comprising:

• at least two successive conduit sections, each conduit section having a coaxially extruded inner wall and outer wall;
• a pair of rigid end portions and at least one undulated portion disposed between said pair of rigid end portions;
• said inner wall and said outer wall forming said rigid end portions and said undulated portion;
• said inner wall being formed of a plastic material which provides good resistance to engine coolant and said outer wall being formed of nylon to provide greater mechanical resistance than provided by said inner wall;
• means for connecting one of said rigid end portions of a first of said conduit sections to one of said rigid end portions of a second of said conduit sections;
• said connecting means comprising annular couplings molded in one piece around the one of said rigid end portions of said first and second conduit sections;
• the other of said pair of rigid portions of said first and second conduit sections facing said engine and said radiator, respectively;
• annular projections provided on portions attached at opposing ends to each of said other rigid end portions;
• end couplings molded integrally with said portions for connecting said flexible conduit to said engine and to said radiator, respectively, said end couplings being constructed of a soft plastic;
• and
• said end couplings having inner cylindrical walls, each of said inner cylindrical walls having inclined annular grooves coacting with said annular projections provided on said portions to provide a coolant-tight connection between said flexible conduit and said engine and between said flexible conduit and said radiator.