Collapsible pump chamber having predetermined collapsing pattern

A manually actuated dispensing pump device for pumping a liquid from a supply container and discharging the liquid through a discharging orifice comprising:

• (a) a housing for sealing mounting the dispensing pump device onto the supply container, the housing including a portion of a liquid passage providing fluid communication from the supply container downstream to the discharge orifice;
• (b) an inlet valve located within the liquid passage, the inlet valve being closed to prevent liquid flow therethrough during periods of positive downstream pressure and being open during periods of negative downstream pressure;
• (c) an outlet valve located within the liquid passage, the outlet valve being open to permit liquid flow therethrough during periods of positive upstream pressure and being closed during periods of negative upstream pressure;
• and
• (d) a collapsible pump chamber defining a portion of the liquid passage downstream of the inlet valve and upstream of the outlet valve, the collapsible pump chamber including a pleated annular side wall defining an internal volumetric portion of the pump chamber and having a structure adapted to collapse in a predetermined pattern in response to a manually compressive force as the pump device is actuated, the predetermined pattern of collapse resulting in an initially relatively small volumetric change in the internal volumetric portion per given stroke length followed by an increased volumetric change in the internal volumetric portion per given stroke length, and the pleated annular side wall having a structure which is sufficiently resilient to expand the collapsible pump chamber upon removal of the manually compressive force.

A manually actuated dispensing pump device for pumping a liquid from a supply container and discharging the liquid through a discharge orifice comprising:

• (a) a housing for sealingly mounting the dispensing pump device onto the supply container, the housing including a portion of a liquid passage providing fluid communication from the supply container downstream to the discharge orifice;
• (b) an inlet valve located within the liquid passage, the inlet valve being closed to prevent liquid flow therethrough during periods of positive downstream pressure and being open during periods of negative downstream pressure;
• (c) an outlet valve located within the liquid passage, the outlet valve being open to permit liquid flow therethrough during periods of positive upstream pressure and being closed during periods of negative upstream pressure;
• and
• (d) a collapsible pump chamber defining a portion of the liquid passage downstream of the inlet valve and upstream of the outlet valve, the collapsible pump chamber having a collapsing side wall defining a portion of the pump chamber, the collapsing side wall having a structure adapted to collapse in a predetermined pattern in response to a manually compressive force as the pump device is actuated, and the collapsing side wall having a structure which is sufficiently resilient to expand the collapsible pump chamber upon removal of the manually compressive force.