| 摘要 |
A tap primarily intended for 'bag-in-a-box' constructions including a plunger (80) which is in a barrel (52). A knob (68) is fast with the plunger (80) and is arranged so that it and the plunger perform a spiral movement when it is rotated. The tap includes a seat (66) with which a sealing portion (86) of the plunger (80) co-operates. The inlet to the barrel is through one end thereof and there is an outlet port (64) in the wall thereof. The part of the plunger (80) outwardly of the sealing portion (86) constitutes a wiping edge which moves across the port (64) during opening and closing movement of the plunger (80). A piercing element (94) is provided which, the first time the tap is opened and closed, is forced through the hermetically sealed pouch (P). The tap is leak-proof, does not permit air to enter the pouch P in normal operation and, because of the wiping action provided, does not drip. |
