Leak-proof sprayer

Claim 1

In a manually operated dispensing pump adapted to be connected to a container for dispensing a liquid product therefrom, wherein the pump includes variable volume means defining a pump chamber, an inlet passageway providing communication between the pump chamber and a liquid reservoir in the container, an inlet check valve operatively disposed within the inlet passageway for permitting the flow of liquid only from the liquid reservoir to the pump chamber, discharge means defining a dispensing orifice, an outlet passageway providing communication between the dispensing orifice and the pump chamber, and an outlet check valve operatively disposed within the outlet passageway for permitting the flow of liquid only from the pump chamber to the dispensing orifice; the improvement wherein the outlet check valve includes a resilient diaphragm operatively disposed within the outlet passageway adjacent to and convexed toward the dispensing orifice, the diaphragm being normally in tensioned engagement with the dispensing orifice and adapted to flex out of engagement therewith when the pressure within the pump chamber and the outlet passageway exceeds the engaging force of the diaphragm, whereby liquid is permitted to flow from the pump chamber through the dispensing orifice and into the atmosphere; and the discharge means and the diaphragm comprise an integrally molded dispenser insert wherein the diaphragm is joined to the discharge means by a flexible hinge and the diaphragm is pivoted about the hinge to engage the dispensing orifice.