Clip unit
A clip unit including: a clip main body having a first arm portion, a second arm portion, and a middle portion; a pressing tube formed in a tube shape to be capable of accommodating the clip main body, the pressing tube being provided to deform the clip main body so as to make a distal end of the first arm portion and a distal end of the second arm portion to approach to each other, as the middle portion, the first arm portion, and the second arm portion are moved toward a proximal end side of the clip unit; a locking portion configured to protrude from an inner circumferential surface of the pressing tube on the proximal end side of the pressing tube; and a first locked portion configured to protrude from a lateral surface of the first arm portion.
1. A clip unit comprising:
a clip main body having a first arm portion, a second arm portion, and a middle portion disposed between a proximal end of the first arm portion and a proximal end of the second arm portion;
a pressing tube formed in a tube shape to be capable of accommodating the clip main body, the pressing tube being provided to deform the clip main body so as to make a distal end of the first arm portion and a distal end of the second arm portion approach to each other, as the middle portion, the first arm portion, and the second arm portion are moved toward a proximal end side of the pressing tube;
a locking portion configured to protrude from an inner circumferential surface of the pressing tube on the proximal end side of the pressing tube; and
a first locked portion configured to protrude from a lateral surface of the first arm portion, the first locked portion being moveable both in a proximal direction and a distal direction with respect to the pressing tube when the first locked portion is located more distal than the locking portion inside the pressing tube,
wherein an opened state of the clip unit is defined as a state in which the distal end of the first arm portion and the distal end of the second arm portion are spaced from each other, and a closed state of the clip unit is defined as a state in which the first arm portion and the second arm portion are deformed to approached each other,
wherein the clip main body is configured to be moved proximally with respect to the pressing tube to deform the first arm portion and the second arm portion such that the clip unit is changed from the opened state to the closed state, and the clip main body is configured to be moved distally with respect to the pressing tube to deform the first arm portion and the second arm portion such that the clip unit is changed from the closed state to the opened state, when the first locked portion is located more distally than the locking portion, and
wherein an advancement of the clip main body with respect to the pressing tube is restricted by an engagement of the first locked portion and the locking portion such that the closed state is maintained, when the first locked portion is located more proximally than the locking portion.
2. The clip unit according to claim 1 , further comprising: a second locked portion configured to protrude from a lateral surface of the second arm portion, wherein, when the first locked portion approaches the second locked portion as the first arm portion approaches the second arm portion by action of the pressing tube, the first locked portion and the second locked portion are movable beyond the locking portion toward the proximal end side of the pressing tube.
3. The clip unit according to claim 2 , wherein the locking portion is provided at a proximal end of the pressing tube, and at least a part of the middle portion protrudes past the proximal end of the pressing tube when the first locked portion is moved beyond the locking portion.
4. The clip unit according to claim 3 , wherein the pressing tube is formed in a cylindrical shape, and the locking portion is formed over an entire inner circumferential surface of the pressing tube so that an edge of the locking portion is formed in a circular shape coaxial with the pressing tube.
5. The clip unit according to claim 4 , wherein the first locked portion includes a distal-end-side end surface formed from a surface substantially orthogonal to a longitudinal axis of the clip main body and a proximal-end-side end surface formed in a tapered shape, and an amount of power necessary to pass the first locked portion through the locking portion from a proximal end side of the locking portion is greater than an amount of power necessary to pass the first locked portion through the locking portion from a distal end side of the locking portion.
6. The clip unit according to claim 5 , wherein an elastic member is provided inside the pressing tube to bias the clip main body against the pressing tube in the distal direction, and the clip main body is moved in the distal direction with respect to the pressing tube by a bias force of the elastic member when the first locked portion is located more distal than the locking portion inside the pressing tube.