Water bed with heater

Claim 1

In combination, a flotation mattress for water beds comprising a water-proof bladder of flexible plastic sheet material having flat, horizontal top and bottom walls, vertical side and end walls and an elongate tubular filler neck with an inner end fixedly related with an opening in one wall of the mattress and extendable outwardly therefrom and having an open outer end, a volume of water within and slackily filling the mattress, an elongate flexible electric heater with an elongate flexible power supply section with a pair of longitudinally extending electrically insulated power lines and having inside and outside portions, said outside portion having an outer free end connected with an electric power supply, a filler neck engaging plug on the power section between the inside and outside portions thereof and engaged in the outer open end portion of the stem with said inside portion extending longitudinally through the stem and into the mattress, an elongate temperature responsive control section with inner and outer ends, means sealingly coupling the outer end of the control section with the inner end of said inside portion and positioned in the water within the mattress, an elongate flexible electric heater section with inner and outer ends positioned within and extending about the interior of the mattress and within the water therein, said heater section has an elongate electrically insulated resistance element extending longitudinally from its outer end to its inner end and thence to its outer end, means sealingly coupling the inner end of the control section with the outer end of the heater section, said control section including an elongate tubular metal heat conducting body normally in heat conducting contact with the water in the mattress, a normally closed temperature responsive switching device with a pair of terminals positioned within the body in heat conducting contact therewith with one terminal connected with one end of the resistance element and the other terminal connected with one of said power lines and means in the body connecting the other end of the resistance element with the other power lines said power supply and heater sections including flexible ground lines extending longitudinally therethrough and means in the body connecting said ground lines.