Molten metal shut-off valve utilizing cooling to solidify metal flow

Claim 1

In a battery grid casting machine having a feed line extending downwardly from a lead pot to a lead dispensing valve, the improvement which comprises, a shut-off valve arranged vertically in said downwardly extending feed line, said shut-off valve having inner and outer sleeves cooperating to define an annular coolant chamber therebetween, means for directing coolant through said chamber and for shutting off the flow of coolant thereto, said inner sleeve having a vertically downwardly extending inlet passageway at its upper end connected to said feed line and an outlet passageway at its lower end connected to said dispensing valve, said inner sleeve also having an intermediate passageway extending vertically between said inlet and outlet passageways, said intermediate passageway being of substantially reduced cross section relative to said inlet passageway and said feed line, said inlet passageway decreasing progressively in cross section to said intermediate passageway, said coolant chamber surrounding said intermediate passageway so that when coolant is directed through said coolant chamber the lead in said intermediate passageway solidifies into a plug which interrupts the flow to the dispensing valve, and means for heating the dispensing valve to maintain the lead therein in a molten condition, said shut-off valve being disposed adjacent and directly above said dispensing valve in heat exchange relation thereto so that when the flow of coolant through said coolant chamber is discontinued the heat transferred from the dispensing valve to the shut-off valve assists in melting the plug of lead solidified therein.