Electric instantaneous water heater

Claim 1

AN ELECTRIC INSTANTANEOUS WATER HEATER COMPRISING AN ELONGATED THIN-WALLED METAL TUBE HAVING A CLOSED AND AN OPEN END, ELECTRIC HEATER MEANS COMPRISING AT LEAST ONE HELICAL COIL COAXIALLY MOUNTED ON THE EXTERIOR OF SAID METAL TUBE AND HAVING A HEATER WIRE AND A TUBULAR METAL SHEATH ENCLOSING SAID WIRE AND INSULATED THEREFROM, SAID COIL HAVING ITS TURNS LOCATED IMMEDIATELY ADJACENT TO EACH OTHER AND METALLICALLY BONDED WITH SAID TUBE, A HELICAL GUIDE STRUCTURE MOUNTED IN SAID TUBE IN COAXIAL RELATION THERETO AND FORMING A HELICAL WATER-FLOW PATH FROM SAID CLOSED END TO SAID OPEN END OF SAID TUBE, PIPE MEANS COMPRISING A PIPE COAXIAL WITH SAID GUIDE STRUCTURE AND EXTENDING AXIALLY WITHIN SAID TUBE, SAID PIPE BEING OPEN AT BOTH ENDS THEREOF FOR THE FLOW OF WATER THERETHROUGH, WATER INLET MEANS COMMUNICATING WITH THE OPEN END OF SAID PIPE AT SAID OPEN END OF SAID TUBE, WATER OUTLET MEANS COMMUNICATING WITH SAID FLOW PATH AT SAID OPEN END OF SAID TUBE, BEING SPACED FROM SAID PIPE AT THE CLOSED END OF SAID TUBE BEING SPACED FROM SAID CLOSED END AND COMMUNICATING WITH SAID FLOW PATH AT SAID CLOSED END FOR PASSING WATER THERTHROUGH FROM SAID WATER INLET MEANS, SAID GUIDE STRUCTURE HAVING A GENERALLY WAVY SURFACE CONFIGURATION ALONG SAID PATH AND BEING LOCATED BETWEEN SAID PIPE AND SAID TUBE AND IN CONTACT WITH BOTH, ELECTRIC CURRENT SUPPLY MEANS CONNECTED WITH SAID HEATER WIRE, AND A WATER MIXER ASSEMBLY OPERATIVELY ASSOCIATED WITH SAID WATER INLET AND OUTLET MEANS FOR SELECTIVELY MIXING HEATED AND UNHEATED WATER.