Connector, infusion set, and medical device connectable to connector

1. A connector that is connectable to a medical device that comprises a female connector portion, the connector comprising:

a main body member comprising:

a cylinder portion that is insertable into the female connector portion of the medical device, and

an engagement member that is fixed in position with respect to the cylinder portion, the engagement member comprising:

a deformation portion that extends in an insertion direction, the insertion direction being a direction in which the cylinder portion is insertable into the female connector portion, the deformation portion being located at a position outside the cylinder portion in a radial direction of the cylinder portion and being elastically deformable in the radial direction, and

a lock portion located at a distal end of the deformation portion, the lock portion being configured to, upon insertion of the cylinder portion into the female connector portion, pass over part of the medical device and then move in a radially inward locking direction to lock the medical device to the connector; and

a lock member that is movable with respect to the main body member, wherein the lock member is configured such that, when the main body member is in a state in which the lock portion locks the medical device to the connector, the lock member is moveable to a lock position at which the lock member limits movement of the lock portion in a radially outward unlocking direction;

wherein the lock member is positioned outside the engagement member in the radial direction and comprises, at an inner surface of the lock member, a level-difference surface that is perpendicular to a longitudinal axis of the lock member and that faces in a distal direction when the lock member is in the lock position;

wherein the engagement member comprises, at an outer wall of the deformation portion, an abutment wall having an abutment wall surface that is perpendicular to a longitudinal axis of the engagement member and that faces in a proximal direction when the lock member is in the lock position; and

wherein the abutment wall is configured to inhibit movement of the lock member to the lock position while the lock portion passes over said part of the medical device by abutting the level-difference surface when the deformation portion is deformed in the radially outward unlocking direction.

2. The connector according to claim 1 , wherein:

the abutment wall is configured to allow movement of the lock member to the lock position after the lock portion passes over said part of the medical device and moves in the radially inward locking direction by not abutting the level-difference surface when the deformation portion is not deformed in the radially outward unlocking direction.

3. The connector according to claim 1 , wherein:

the lock portion comprises a lock claw that protrudes inward from the deformation portion in the radial direction.

4. The connector according to claim 3 , wherein:

the lock member comprises a reception portion configured to receive at least part of the deformation portion elastically deformed in the radial direction; and

the level-difference surface is located in the reception portion.

5. An infusion set comprising the connector according to claim 1 .

6. A method of using an assembly comprising a medical device and a connector, the method comprising:

providing a medical device that comprises a female connector portion;

providing a connector that comprises:

a main body member comprising:

a cylinder portion that is insertable into the female connector portion of the medical device, and

an engagement member that is fixed in position with respect to the cylinder portion, the engagement member comprising:

a deformation portion that extends in an insertion direction, the insertion direction being a direction in which the cylinder portion is insertable into the female connector portion, the deformation portion being located at a position outside the cylinder portion in a radial direction of the cylinder portion and being elastically deformable in the radial direction, and

a lock portion located at a distal end of the deformation portion, the lock portion being configured to, upon insertion of the cylinder portion into the female connector portion, pass over part of the medical device and then move in a radially inward locking direction to lock the medical device to the connector, and

a lock member that is movable with respect to the main body member, wherein the lock member is configured such that, when the main body member is in a state in which the lock portion locks the medical device to the connector, the lock member is moveable to a lock position at which the lock member limits movement of the lock portion in a radially outward unlocking direction;

wherein the lock member is positioned outside the engagement member in the radial direction and comprises, at an inner surface of the lock member, a level-difference surface that is perpendicular to a longitudinal axis of the lock member and that faces in a distal direction when the lock member is in the lock position, and

wherein the engagement member comprises, at an outer wall of the deformation portion, an abutment wall having an abutment wall surface that is perpendicular to a longitudinal axis of the engagement member and that faces in a proximal direction when the lock member is in the lock position;

inserting the cylinder portion into the female connector portion;

causing the lock portion to pass over said part of the medical device; and

inhibiting movement of the lock member to the lock position while the lock portion passes over said part of the medical device by the abutment wall abutting the level-difference surface when the deformation portion is deformed in the radially outward unlocking direction.