| 摘要 |
A cartridge assembly having a cylindrical body, with its forward end being packed down to form an annular flange, a hub fitted on the annular flange, a diaphragm seal positioned on the forward face of the annular flange and held in sealing position by the hub fitted on the annular flange, a piston slidably carried in the rearward portion of the body, a liquid medicament held in the body in the space between the diaphragm and the piston, the hub being made of transparent plastic material and having a first cylindrical portion having an internal diameter sized to fit over the annular flange of the cartridge, a second cylindrical portion extends from the first cylindrical portion and has a diameter less than the first cylindrical portion, a third cylindrical portion extends from the second cylindrical portion and has a diameter less than the second cylindrical portion, a fourth cylindrical portion extends from the third cylindrical portion and has a diameter less than the third cylindrical portion, the fourth cylindrical portion having an internal diameter sized to receive the non-patient end of the needle, the chamber formed by the second cylindrical portion constitutes the chamber for the ballooning of the diaphragm when under medicament pressure, this chamber being provided with a spike having its point directed toward the diaphragm and adapted to pierce same upon sufficient ballooning thereof.
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