Patent ID: 7320680
Filing Date: 2008-01-22
Classification: A61M

Abstract:
1. A single-use syringe adapted to be used with a needle assembly, comprising: a barrel having an inner surrounding barrel surface which surrounds an axis in a longitudinal direction, and which includes a rear larger-diameter portion that defines a rear passageway therein, a front smaller-diameter portion that defines a front passageway therein to be in fluid communication with the needle assembly and that is opposite to said rear larger-diameter portion in the longitudinal direction, and a surrounding shoulder that is disposed between said rear larger-diameter portion and said front smaller-diameter portion, said rear passageway terminating at a rearward opening; a plunger which is disposed to be movable in said rear passageway along said rear larger-diameter portion, said plunger having a front end wall which confronts said front passageway, and a rear end wall which is disposed opposite to said front end wall and which extends outwardly of said rearward opening to be manually operable; a carrier including a tail portion which extends from said front end wall along the axis, a head portion which is disposed opposite to said tail portion in said rear passageway along the axis, and an intermediate surrounding portion which is interposed between said tail and head portions and which surrounds the axis, said intermediate surrounding portion having a pushing region and a retained region which are proximate to said tail and head portions, respectively; and a hollow deformable sealing member including a head end wall which has a periphery and which confronts said surrounding shoulder, an upper sealing end which is integrally formed with said periphery of said head end wall and which is in fluid-tight and slidable engagement with said rear larger-diameter portion, and a deformable surrounding wall which extends from said upper sealing end rearwardly and which terminates at a surrounding trailing end that is configured to drag on said rear larger-diameter portion, said deformable surrounding wall having an outer surrounding wall surface which is spaced apart from said rear larger-diameter portion in radial directions when said syringe is in a position of use, thereby vesting said deformable surrounding wall with an increased radial flexibility, and an inner surrounding wall surface which is opposite to said outer surrounding wall surface in radial directions, said inner surrounding wall surface having a yielding segment which is engaged with and which is depressed by said pushing region radially when said carrier is moved in a longitudinal direction relative to said deformable surrounding wall so as to bring said head end wall to abut against and to be retained at said surrounding shoulder, thereby displacing said syringe from the position of use to a disposal position, and a retaining segment which is in a first frictional engagement with said retained region by virtue of a first frictional force so as to confine, in cooperation with said yielding segment and said pushing region, a fluid-tight surrounding area, and which is configured such that the first frictional force is diminished so as to facilitate release of said retained region from said retaining segment when said yielding segment is depressed by said pushing region, thereby disrupting fluid-tightness of said surrounding area and rendering the syringe unreusable.