| 摘要 |
<p>1326848 Liquid injecting apparatus MPL INC 26 Oct 1971 [10 Nov 1970] 49767/71 Heading A5R To separate the liquid L from the metallic cannula 45 before use, pre-filled liquid dispensing apparatus comprises a barrel 21 defining a chamber for the liquid, having a constricted mouth 26 in which is wedged a rubber valve plug 51, and a by-pass chamber 46 of larger diameter than the mouth 26, so that on operating a piston 63 the plug 51 is forced out of the mouth 26 into the by-pass chamber and allows the liquid to pass to the cannula 45 via the mouth 26 and the by-pass chamber. The plug has a cylindrical mid-section 53 and has its ends tapered and of cruciform shape so that it does not prevent liquid from leaving the by-pass chamber. The apparatus may take the form of either a syringe, or of a disposable cartridge which fits into a syringe body. The apparatus may be used for either dispensing or aspirating liquid. The unstressed diameter of the plug is smaller than that of the by-pass chamber, and is sufficiently larger than that of the mouth to prevent it from being forced back into the mouth. The plug is longer than the internal diameter of the by-pass chamber.</p> |
