| 摘要 |
A delivery system (10) includes a tube (11) having a central passageway (12) and a dispensing orifice (22) and a venting orifice (23, 50). An amount of the material to be dispensed is drawn into the central passageway (12), after which the venting orifice (23, 50) is closed off, causing the material within the central passageway (12) to remain due to unequal pressures between the central passageway (12) and the atmosphere, until the venting orifice (23, 50) is again uncovered. A squeeze pump (40) may be positioned between the dispensing orifice (22) and the dispensing orifice (23) to be pinched, thereby drawing liquid into or dispensing liquid from the central passageway (12). |
