Patent ID: 7534232
Filing Date: 2009-05-19
Classification: A61M

Abstract:
1. An indwelling needle composed of a needle having a sharp edge formed a tip of a distal end thereof, a tubular hub for holding the needle at a proximal end thereof, and a tubular protective cover surrounding and slidable along the needle, the indwelling needle being switchable between a use state in which the protective cover is relatively moved toward the proximal end of the needle in an axial direction thereof so that the sharp edge of the needle projects from the protective cover and a housed state in which the protective cover is relatively moved toward the distal end of the needle in the axial direction thereof so that the sharp edge of the needle is housed in the protective cover, said indwelling needle comprising: a tubular body for being fixed to an attaching object such that the tubular body slidably retains the protective cover and the hub in the needle's axial direction so that the needle slidably passes through the body and the protective cover, a spring elastically fitted between the body and the protective cover so as to urge the body and the protective cover toward the proximal and distal ends of the needle in the axial direction thereof respectively, a first retention mechanism configured to retain the hub and the needle in a use state, provided between the hub and the body and comprising a first projection projecting from the hub toward the body and having proximal and distal ends, an end face at the proximal end of the first projection in the needle's axial direction being engaged with an end face at a distal end of a first engaging portion in the needle's axial direction formed on the body so as to retain the use state preventing the hub from being retracted relative to the body, whereby the hub and the needle are extended in the needle's axial direction relative to the body, and a second retention mechanism configured to retain the protective cover in the use state, provided between the body and the protective cover and comprising a second projection projecting from the protective cover toward the body and having proximal and distal ends, an end face at the distal end of the second projection in the needle's axial direction being engaged with an end face at a proximal end of a second engaging portion in the needles s axial direction formed on the body so as to retain the use state preventing the protective cover from being advanced relative to the body, whereby the protective cover is retracted toward the proximal end of the needle in the axial direction thereof relative to the body against an elastic force of the spring, the second retention mechanism being released by releasing the first retention mechanism so that the hub and needle are retracted relative to the body in the needle's axial direction by a necessary amount, whereby the protective cover is advanced toward the distal end of the needle in the axial direction thereof relative to the body with the elastic force of the spring to achieve the housed state and the first projection presses the second projection when the hub is retracted relative to the body to release an engaged state of the second projection and the second engaging portion, so that the protective cover is advanced relative to the body by the elastic force of the spring.