| 摘要 |
<p>A variable volume bag (1) comprises a bag casing (2) and an air bag (3) received in the bag casing (2) and capable of expansion and contraction. The air bag (3) comprises an air bag casing (4) and a plugged feed and discharge port (5) for permitting feeding of air into and discharging of air from the air bag casing (4).</p> |
