Patent ID: 7311227
Filing Date: 2007-12-25
Classification: B05B

Abstract:
1. A manually operated, liquid dispensing trigger sprayer comprising: a sprayer housing; a liquid pump on the sprayer housing, the liquid pump including a pump chamber and a liquid piston mounted in the pump chamber for reciprocating movements of the liquid piston between first and second positions of the liquid piston in the pump chamber on operation of the liquid pump; a liquid discharge passage extending through the sprayer housing and communicating with the liquid pump for directing liquid from the liquid pump, through the sprayer housing, and discharging the liquid from the sprayer housing on operation of the liquid pump; a trigger mounted on the sprayer housing for movement of the trigger relative to the sprayer housing, the trigger being operatively connected to the liquid pump for operation of the liquid pump in response to movement of the trigger; a vent chamber on the sprayer housing, the vent chamber having a cylindrical interior surface, the vent chamber interior surface having opposite first and second end sections with respective first and second interior diameter dimensions, the first interior diameter dimension being smaller than the second interior diameter dimension; and, a vent piston in the vent chamber and operatively connected to the liquid piston for movement of the vent piston between the first and second end sections of the vent chamber in response to the liquid piston moving between the respective first and second positions of the liquid piston in the pump chamber, the vent piston engaging with the vent chamber interior surface in both the first and second end sections of the vent chamber.