A container-mounted pump dispenser having a body with a vertical cylinder and piston is provided with a one-piece spring/gasket. The spring/gasket is a resilient bowl-shaped spring attached at its lower end about the piston stem and at its upper end comprises an annular gasket to be squeezed between...http://www.google.fr/patents/US6123236?utm_source=gb-gplus-shareBrevet US6123236 - Pump dispenser having one-piece spring and gasket
