Syringe

A syringe detachably assembled with a medicine vial containing medicament liquid and a needle component connected to a front end of the medicine vial, characterized in that, the syringe defines a central axis extending along a front-to-back direction of the syringe;

• the syringe comprises an injection mechanism;
• the injection mechanism has an injection mode and a standby mode, and is able to be manually triggered to perform a conversion between the injection mode and the standby mode;
• the injection mechanism comprises:
• a housing having a movable space formed through the housing along the central axis, a front end of the housing detachably connected to the medicine vial;
• and a one-way ratchet portion formed on a peripheral wall of the movable space at a front segment of the movable space of the housing;
• a spiral pushing assembly mounted in the movable space of the housing and being capable of spirally moving around the central axis;
• the spiral pushing assembly extending to an outside of a rear end of the housing;
• and the spiral pushing assembly being able to be pushed to generate a spiral propulsion;
• a metering guide sleeve mounted in the housing, being capable of rotating at a fixing point;
• and the metering guide sleeve inserted into the spiral pushing assembly and able to be controlled to connect and rotate with the spiral pushing assembly;
• the metering guide sleeve comprising a guide sleeve body and multiple non-return ratchet buckles;
• the guide sleeve body having a guide sleeve central hole, at least one spiral portion formed on an inner peripheral wall of the guide sleeve central hole;
• a guide sleeve threaded portion formed on a rear segment of an outer peripheral surface of the guide sleeve body;
• and a guide sleeve front end portion formed at a front end of the guide sleeve body;
• the multiple non-return ratchet buckles formed on an external surface of the guide sleeve front end portion;
• when the multiple non-return ratchet buckles controlled to engage with the one-way ratchet portion of the housing, the metering guide sleeve solely driven to rotate forwardly and in said injection mode;
• when the multiple non-return ratchet buckles disengaging from the one-way ratchet portion of the housing, the metering guide sleeve able to rotate forwardly or backwardly and in said standby mode;
• a total volume control nut mounted in the spiral pushing assembly, being capable of linearly moving along the central axis, and screwed with the guide sleeve threaded portion at a rear segment of the metering guide sleeve;
• a diagonal tension knob mounted in the front end of the housing and being movable along the central axis;
• the diagonal tension knob being drivable to change an engaging condition of the non-return ratchet buckles relative to the one-way ratchet portion of the housing and to convert the said injection mode and the said standby mode;
• and
• a metering screw inserted in the diagonal tension knob and the housing and the metering screw screwed within the metering guide sleeve;
• the metering screw having a screw body having a screw threaded portion and the metering screw screwed with said at least one spiral portion inside the metering guide sleeve via the screw threaded portion;
• a front end of the metering screw extending in front of the diagonal tension knob;
• a spiral movement of the metering guide sleeve able to drive the metering screw to move linearly along the central axis inside the housing to perform a quantitative output of the medicament liquid in the medicine vial;
• when the injection mechanism in the standby mode, the metering screw being able to linearly move backward and be received into the housing along the central axis.