High volume dispensing pump with shortened axial travel

A pump dispenser having an external pump engine including a pump chamber positioned above the radial sealing flange of an H-style closure cap, the dispenser comprising:

• a closure element including:
• (i) a cap having a radial flange defining an inlet bore and at least one air return vent, a lower skirt extending below the radial flange, and an upper skirt, (ii) a valve sealing the inlet bore, and (iii) a sleeve received within the upper skirt, the sleeve having at least one vent aperture and wherein return air pathways are provided between the sleeve and the upper skirt and communicate with the air return vent;
• an actuator including an outlet nozzle and a piston stem and wherein the piston stem has hollow tube communicating with the outlet nozzle through an outlet bore and an annular wiper configured to seal to and slide along an inner facing of the sleeve;
• and
• a biasing member positioned between the piston stem and radial flange and urging the actuator away from the closure element.