Patent ID: 8474656
Filing Date: 2013-07-02
Classification: A61C,B05C

Abstract:
1. A dispenser for extruding a viscous material, the dispenser comprising: a syringe body having a space for filling contents and equipped with an extruding nozzle at a front end thereof, a plunger that can slide in the syringe body by a pressing force applied thereto in order to extrude the contents in the filling space from a tip of the extruding nozzle, an O-ring placed in an annular groove formed in a front end section of the plunger and slidable on an inner wall surface of the syringe body, wherein the annular groove is formed as a recess having a flat bottom wall and defined by a conical disc that is arranged at a front end of the plunger and a pressing disc that is spaced backwardly from the conical disc, and wherein the O-ring contacts directly with the flat bottom wall, and a plurality of projections or grooves formed on the pressing disc at intervals therebetween so that a side portion of the O-ring comes into contact with the sidewall of the annular groove, is elastically displaced and then compressively deformed upon pressing and so that the O-ring is restored upon releasing a load applied for pressing the plunger to slide the plunger in a direction opposed to the pressing direction, thus inducing back suction of contents.