Patent ID: 7351229
Filing Date: 2008-04-01
Classification: A61M

Abstract:
1. An injector for liquid medicines comprising: a cylindrical body having an opening at proximal and distal ends thereof and provided with a fluid inlet and a fluid outlet on opposite sides of the cylindrical body, axes of the fluid inlet and fluid outlet being substantially perpendicular to axes of the openings of the proximal and distal ends of the cylindrical body, said inlet and said outlet respectively communicating with a lumen of the cylindrical body, said inlet opening at a position closer to the distal end of the cylindrical body than where the fluid outlet opens; and a plurality of gaskets displaced relative to each other and being fluid-tight and slidably arranged in the lumen of said cylindrical body and adapted to be moved along an inner wall of said cylindrical body, said plurality of gaskets forming at least one fluid chamber therebetween, said at least one fluid chamber being filled with a liquid medicine; a first gasket of said plurality of gaskets being provided with a flow path and being slidable from a first position where the fluid inlet and outlet are communicated with one another through the flow path of the first gasket, to the distal end of the cylindrical body via a second position where said at least one fluid chamber is prevented from fluid-communication with the fluid inlet but communicating with the fluid outlet to inject the liquid medicine in the fluid chamber through the fluid outlet, a second gasket of said plurality of gaskets has sealing portions on each end thereof and is provided with a flow path between the sealing portions to allow the fluid inlet of the cylindrical body to communicate with the fluid outlet through the flow path thereof when the first gasket is moved to the distal end of cylindrical body along with the second gasket, and wherein at least one of the proximal end of the first gasket and the distal end of the second gasket is provided with a cylindrical projection having an outer diameter smaller than an inner diameter of the cylindrical body and projecting into the fluid chamber so that said first gasket and/or second gasket allow the fluid inlet to communicate with the fluid outlet through an annular gap formed between the projections thereof and the inner wall of the cylindrical body when said first gasket is moved to the distal end of the cylindrical body.