Flow-activated resistance heater for water

In an apparatus for heating water including a hollow body through which a stream of water is permitted to flow, said body defining a heating chamber in which is positioned an electrical resistance heater, said body also having a receiving chamber therein for receiving the inflowing water and an intermediate duct for providing flow of water from said receiving chamber into said heating chamber, and activator means for energizing the resistance heater only in response to the flow of water into said receiving chamber, said activator means including piston means movably positioned within said body for effectively separating said receiving chamber from said intermediate duct, said piston means having small opening means associated therewith for restricting flow of water from said receiving chamber into said intermediate duct, said piston means being normally maintained in an inactive position under nonflow conditions and being moved a limited extent into an activated position in response to flow of water into said receiving chamber, electrical switching means positioned exteriorly of said body for selectively energizing or de-energizing said resistance heater, and lever-type link means operatively connected between said piston means and said switch means for activating said switch means to energize said heater when said piston means is moved into its activated position responsive to flow of water, said link means having a portion thereof projecting into said intermediate duct and operatively connected to said piston means, said link means projecting through the wall of said body and having a portion thereof projecting exteriorly of said body for operative cooperation with said switch means, the improvement wherein said body includes a tubular portion defining therein said intermediate duct, said switch means including a pair of stationary contacts disposed exteriorly of said tubular portion adjacent one side thereof, said switch means including a further pair of movable contacts disposed closely adjacent and in opposed relationship to said fixed contacts, said movable contacts being connected to and movable by a carrier which is movably supported adjacent the exterior of said tubular portion for movement in a direction substantially parallel with the axis of said tubular portion, said carrier being connected to the exteriorly projecting portion of said link means, said movable contacts being associated with a pair of substantially semicircular springlike conductive plates which are disposed in opposed relationship and substantially encircle the tubular portion, said carrier being connected between said springlike plates adjacent one end thereof and said movable contacts also being disposed adjacent said one end of said springlike plates, the other opposed ends of said springlike plates being fixedly positioned relative to said body and disposed relative to said tubular portion substantially diametrically opposite from said carrier, one said pair of contacts being electrically connected to said heater, and the other said pair of contacts being joined to a source of electrical energy.