Abstract: A pump device adapted to be mounted on a liquid container includes a nozzle head formed on a top portion of a piston reciprocatively held in a liquid accumulator mounted on the liquid container, a restoring spring resiliently retained between the nozzle head and a fastening ring which is secured on an upper portion of the accumulator, a container cap secured on a top portion of the liquid container and fastened between the fastening ring and a flange of the accumulator, a suction tube connected to the accumulator and inserted in the liquid container for sucking liquid into the accumulator; characterized in that the restoring spring is disposed around a piston rod outside an interior of the pump and of the accumulator to prevent contamination of the liquid by the spring or to prevent corrosion of the spring by the liquid.

Abstract: An improved pump-head structure, which has a valve annulus mounted on the inlet to the lower end of a liquid accumulator of the pump-head structure to prevent leakage of a liquid from the liquid accumulator. A plunger valve is connected to the valve annulus via a spring piece, which exerts a downward force on the plunger valve and thus maintains the inlet of the lower end of the liquid accumulator forcedly and tightly closed under normal conditions by the downward action of the plunger valve.