| 摘要 |
<p>A vent tube incorporating a non-return valve is fitted into the casing of a refrigerator to break any vacuum due to cooling of entrapped warm air and hence facilitate reopening of the door. The vent assembly is fitted between the base of the food compartment and the supporting chasis and pref. incorporates a downpipe moulded from polypropylene, a valve seat moulded from polyethylene to support a ball made from low density material, and an adaptor moulded from polyethylene to connect the vertical vent radially to the refrigerated compartment. The vent components are relatively inexpensive and resistant to cool or moist conditions. The vent is relatively large and less prone to blocking by frost than simple small bore vents. The vent pipe bore is stepped to prevent excessive travel by the ball.</p> |
