| 摘要 |
The dispensing head disclosed comprises a chamber (2) with a bottom outlet (3), and a coaxial hollow plunger (8) the bottom end of which carries a plug (10) that registers in the outlet. The plunger is capable of axial shift between a raised position, and a lowered position in which the plug (10) blocks the outlet (3); on completion of the single batching cycle, the plug is lowered into the outlet and pressurized inert gas is directed through the plunger. The head also comprises a poppet (16) capable of axial movement between a raised position, in which it registers in the bore (11) of the plug (10), and a lowered position in which it is distanced from the mouth of the bore; the poppet is fixed to the bottom end of a slender stem (17) accommodated within the hollow plunger (8), and reciprocated in such a way that it keeps the bore (11) normally closed, and is moved into the lowered position only when the plug (10) happens likewise to be in its lowered position.
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