| 摘要 |
A syringe for use in dispensing infinitesimally small, accurately measured quantities of fluid. The syringe is comprised generally of a tubular body, a needle and lateral vent-valve assembly mounted in the forward end of the tubular body. The needle and lateral vent-valve assembly comprises a resilient tubular body, a tubular plunger guide mounted at one side thereof and within the axial opening of the tubular body, a needle mounted on the resilient tubular body at the forward or opposite side of the tubular guide and an on-off valved lateral vent communicated to the bores through the hollow needle, the resilient tubular member and the plunger guide. The plunger assembly includes a telescoping tubular member which is reciprocably mounted upon the plunger guide, and a wire plunger associated therewith which extends through the bore of the plunger guide, the resilient tubular member with which it is snugly fitted and sealed, and is loosely fitted through the bore of the needle. The wire plunger traverses the length of the needle and the annulus formed between the external surface of the plunger and inter wall surface of the needle can be readily cleaned or filled with an accurately measured quantity of fluid when the valve is open and injected when the valve is closed.
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