| 摘要 |
<p>A piston device comprises a sleeve (21), a casing pipe (23), a first piston (21), a resilient member (22), and a second piston (25). The first piston is arranged to sheathe the casing pipe at a position proximate to the closed end of the casing pipe for selectively covering and exposing the through hole by a reciprocate movement. The resilient member is installed in side the sleeve at a position between the closed end of the sleeve and the first piston while ensheathing the casing pipe therethrough. The second piston is arranged to sheathe the sleeve at a position proximate to its open end. Moreover, by combining the piston device with a container containing fluid and gas, a fluid/gas drawing apparatus can be formed, and, by combining the fluid/gas drawing apparatus with a nozzle, a foam producing apparatus capable of producing thick foams can be formed.</p> |
