| 摘要 |
620,824. Hypodermic syringe. DOLDER, E. Jan. 28, 1947, No. 2583. [Class 81(ii)] In a hypodermic &c. syringe including a cylindrical ampoule &c. inserted in the casing and closed at both ends by plugs or a plug and cap, the front plug or cap being punctured by the injecting needle and the rear plug serving as a plunger by means of a plunger rod, the plunger is made of elastic material and provided with means for axial compression and radial expansion to vary the sealing pressure of the plunger against the wall of the ampoule and permitting the syringe also to be used for withdrawing liquid. The syringe comprises a casing 1 into which the ampoule plug 2 or cap and a rear closure plug 3 is inserted, the plug 2 being punctured by the cannula 6 when operating the syringe. The rear plug 3 is provided with a bolt 9 having a head 10 and passing through a washer 12, the end of the bolt being engaged by a nut 13 having two lateral inclined faces 14 and recessed portions by means of which the plunger 3 is gripped and operated by the plunger rod 15 in the form of a tube. One end of the plunger rod is secured to the handle 16 and the other end is slotted at 17 to form two resilient parts adapted to engage the nut 13 to operate the plunger 3. The plunger rod 15 is provided with an axially movable bar 24 having an arrow head 26 by means of which the resilient parts of the plunger rod 15 may be forced apart when it is desired to disengage the plunger rod 15 from the plunger 3. When it is desired to vary the sealing or sliding pressure of the plunger 3 against the glass casing 4 the plunger bar 15 is engaged with the nut 13 and rotation of the bar 15 varies the axial compression, and therefore the radial expansion of the plunger 3. In this way when the syringe is used to withdraw liquid into the casing 4 the plunger 3 on completion of its stroke may be compressed so that the liquid is sealed in the casing 4 which may then be removed from the syringe. The front plug 2 may be arranged to vary the sealing pressure by axial compression and radial expansion. In a modification the disengaging bar 24 is in the form of a tube within which is a rod having a nib engageable with the nut 13 whereby the nut may be turned by manual manipulation of the rod. |
