Patent ID: 9125996
Filing Date: 2015-09-08
Classification: A61M

Abstract:
1. A liquid injection instrument comprising: an internal structural body having a protector that is disposed on an outer circumferential side of the internal structural body movably relative to the internal structural body along the axial direction, and has a tubular shape and a distal opening; wherein the protector is capable of taking wherein the protector has an outside engagement piece that is provided in a tube wall of the protector and is elastically deformed, the cylindrical body has an inside engagement piece that is provided at a proximal part of the cylindrical body, engages with the outside engagement piece in the fourth state, and is elastically deformed, and the plunger has a pressing portion that presses and deforms the inside engagement piece outward in the fourth state, wherein in the third state, the pressing portion of the plunger moved in the distal direction presses and expands the outside engagement piece outward collectively with the inside engagement piece, and wherein in the fourth state, the outside engagement piece returns to an original shape, and the inside engagement piece remains pressed and deformed outward by the pressing portion to engage directly with the outside engagement piece, so that the movement of the protector in a proximal direction is prohibited by the engagement.