Indwelling needle assembly

An indwelling needle assembly comprising:

• an outer needle hub;
• an inner needle inserted into the outer needle hub;
• and
• a safety mechanism part externally mounted about the inner needle and is configured to protect a needle tip of the inner needle when the inner needle is pulled out of the outer needle hub,
• wherein the safety mechanism part includes at least one urging part urged in a direction of approaching the inner needle and a block part that is in contact with the urging part such that the urging part is kept remote from the inner needle, the block part includes an inner-needle engaging part that is engaged with the inner needle in an axial direction, and the urging part and the block part are movable relative to each other in a lengthwise direction of the inner needle,
• the safety mechanism part further includes an outer-needle-hub engaging part that is engaged with an outer surface of the outer needle hub and an engaging-part opposing wall that is positioned in opposition to the outer-needle-hub engaging part and limits displacement of the outer needle hub in a direction of disengagement from the outer-needle-hub engaging part by being in contact with the outer needle hub, and relative rotation of the outer-needle-hub engaging part and the engaging-part opposing wall around the inner needle is restricted,
• at least one of the outer-needle-hub engaging part and the engaging-part opposing wall is configured to displace integrally with the urging part,
• by the inner needle being pulled out of the outer needle hub, the block part engaged with the inner needle by the inner-needle engaging part is configured to move relative to the urging part to be in a state of non-contact, while the urging part is configured to displace in the direction of approaching the inner needle such that the needle tip of the inner needle is prevented from protruding from the safety mechanism part and engagement of the outer needle hub with the safety mechanism part is allowed to be released,
• the engaging-part opposing wall extends to an inside of the outer needle hub, and
• the engaging-part opposing wall is made of synthetic resin.

An indwelling needle assembly comprising:

• an outer needle hub;
• an inner needle inserted into the outer needle hub;
• and
• a safety mechanism part externally mounted about the inner needle and is configured to protect a needle tip of the inner needle when the inner needle is pulled out of the outer needle hub,
• wherein the safety mechanism part includes at least one urging part urged in a direction of approaching the inner needle and a block part that is in contact with the urging part such that the urging part is kept remote from the inner needle, the block part includes an inner-needle engaging part that is engaged with the inner needle in an axial direction, and the urging part and the block part are movable relative to each other in a lengthwise direction of the inner needle,
• the safety mechanism part further includes an outer-needle-hub engaging part that is engaged with an outer surface of the outer needle hub and an engaging-part opposing wall that is positioned in opposition to the outer-needle-hub engaging part and limits displacement of the outer needle hub in a direction of disengagement from the outer-needle-hub engaging part by being in contact with the outer needle hub, and relative rotation of the outer-needle-hub engaging part and the engaging-part opposing wall around the inner needle is restricted,
• at least one of the outer-needle-hub engaging part and the engaging-part opposing wall is configured to displace integrally with the urging part,
• by the inner needle being pulled out of the outer needle hub, the block part engaged with the inner needle by the inner-needle engaging part is configured to move relative to the urging part to be in a state of non-contact, while the urging part is configured to displace in the direction of approaching the inner needle such that the needle tip of the inner needle is prevented from protruding from the safety mechanism part and engagement of the outer needle hub with the safety mechanism part is allowed to be released, and
• the engaging-part opposing wall is engaged with the outer surface of the outer needle hub.

An indwelling needle assembly comprising:

• an outer needle hub;
• an inner needle inserted into the outer needle hub;
• a safety mechanism part externally mounted about the inner needle and is configured to protect a needle tip of the inner needle when the inner needle is pulled out of the outer needle hub;
• and
• a plate spring,
• wherein the safety mechanism part includes at least one urging part urged in a direction of approaching the inner needle and a block part that is in contact with the urging part such that the urging part is kept remote from the inner needle, the block part includes an inner-needle engaging part that is engaged with the inner needle in an axial direction, and the urging part and the block part are movable relative to each other in a lengthwise direction of the inner needle,
• the safety mechanism part further includes an outer-needle-hub engaging part that is engaged with an outer surface of the outer needle hub and an engaging-part opposing wall that is positioned in opposition to the outer-needle-hub engaging part and limits displacement of the outer needle hub in a direction of disengagement from the outer-needle-hub engaging part by being in contact with the outer needle hub, and relative rotation of the outer-needle-hub engaging part and the engaging-part opposing wall around the inner needle is restricted,
• at least one of the outer-needle-hub engaging part and the engaging-part opposing wall is configured to displace integrally with the urging part,
• by the inner needle being pulled out of the outer needle hub, the block part engaged with the inner needle by the inner-needle engaging part is configured to move relative to the urging part to be in a state of non-contact, while the urging part is configured to displace in the direction of approaching the inner needle such that the needle tip of the inner needle is prevented from protruding from the safety mechanism part and engagement of the outer needle hub with the safety mechanism part is allowed to be released, and
• the urging part is made of synthetic resin at least in a portion that is in contact with the block part, and the portion made of synthetic resin is urged by the plate spring in the direction of approaching the inner needle.

An indwelling needle assembly comprising:

• an outer needle hub;
• an inner needle inserted into the outer needle hub;
• and
• a safety mechanism part externally mounted about the inner needle and is configured to protect a needle tip of the inner needle when the inner needle is pulled out of the outer needle hub,
• wherein the safety mechanism part includes at least one urging part urged in a direction of approaching the inner needle and a block part that is in contact with the urging part such that the urging part is kept remote from the inner needle, the block part includes an inner-needle engaging part that is engaged with the inner needle in an axial direction, and the urging part and the block part are movable relative to each other in a lengthwise direction of the inner needle,
• the safety mechanism part further includes an outer-needle-hub engaging part that is engaged with an outer surface of the outer needle hub and an engaging-part opposing wall that is positioned in opposition to the outer-needle-hub engaging part and limits displacement of the outer needle hub in a direction of disengagement from the outer-needle-hub engaging part by being in contact with the outer needle hub, and relative rotation of the outer-needle-hub engaging part and the engaging-part opposing wall around the inner needle is restricted,
• at least one of the outer-needle-hub engaging part and the engaging-part opposing wall is configured to displace integrally with the urging part,
• by the inner needle being pulled out of the outer needle hub, the block part engaged with the inner needle by the inner-needle engaging part is configured to move relative to the urging part to be in a state of non-contact, while the urging part is configured to displace in the direction of approaching the inner needle such that the needle tip of the inner needle is prevented from protruding from the safety mechanism part and engagement of the outer needle hub with the safety mechanism part is allowed to be released, and
• the block part has a plate shape.

An indwelling needle assembly comprising:

• an outer needle hub;
• an inner needle inserted into the outer needle hub;
• and
• a safety mechanism part externally mounted about the inner needle and is configured to protect a needle tip of the inner needle when the inner needle is pulled out of the outer needle hub,
• wherein the safety mechanism part includes at least one urging part urged in a direction of approaching the inner needle and a block part that is in contact with the urging part such that the urging part is kept remote from the inner needle, the block part includes an inner-needle engaging part that is engaged with the inner needle in an axial direction, and the urging part and the block part are movable relative to each other in a lengthwise direction of the inner needle,
• the safety mechanism part further includes an outer-needle-hub engaging part that is engaged with an outer surface of the outer needle hub and an engaging-part opposing wall that is positioned in opposition to the outer-needle-hub engaging part and limits displacement of the outer needle hub in a direction of disengagement from the outer-needle-hub engaging part by being in contact with the outer needle hub, and relative rotation of the outer-needle-hub engaging part and the engaging-part opposing wall around the inner needle is restricted,
• at least one of the outer-needle-hub engaging part and the engaging-part opposing wall is configured to displace integrally with the urging part,
• by the inner needle being pulled out of the outer needle hub, the block part engaged with the inner needle by the inner-needle engaging part is configured to move relative to the urging part to be in a state of non-contact, while the urging part is configured to displace in the direction of approaching the inner needle such that the needle tip of the inner needle is prevented from protruding from the safety mechanism part and engagement of the outer needle hub with the safety mechanism part is allowed to be released, and
• the urging part includes a needle restricting part that is configured to come into contact with a side surface of the inner needle, and by the inner needle being pulled out of the outer needle hub, the needle restricting part is configured to come into contact with the side surface of the inner needle such that the needle tip of the inner needle is prevented from protruding from the safety mechanism part.

An indwelling needle assembly comprising:

• an outer needle hub;
• an inner needle inserted into the outer needle hub;
• and
• a safety mechanism part is externally mounted about the inner needle and is configured to protect a needle tip of the inner needle when the inner needle is pulled out of the outer needle hub,
• wherein the safety mechanism part includes an urging part urged in a direction of approaching the inner needle and a block part that is in contact with the urging part such that the urging part is kept remote from the inner needle, the block part includes an inner-needle engaging part that is engaged with the inner needle in an axial direction and a peripheral wall part on which the urging part is held in contact and being disposed about the inner needle with a radial space therebetween so that the peripheral wall part is radially spaced away from the inner needle, and the urging part and the block part are movable relative to each other in a lengthwise direction of the inner needle,
• the outer needle hub is provided with an engaging projection on an outer surface thereof,
• the safety mechanism part further includes an outer-needle-hub engaging part that is engaged with the engaging projection and an engaging-part opposing wall that limits disengaging displacement of the outer-needle-hub engaging part radially outward from the engaging projection by coming into contact with an inner surface of the outer needle hub,
• an amount of displacement to be limited by the engaging-part opposing wall coming into contact with the inner surface of the outer needle hub is set so as not to reach an amount of displacement required for disengagement of the outer-needle-hub engaging part radially outward from the engaging projection in every axis-perpendicular direction of the outer needle hub,
• at least one of the outer-needle-hub engaging part and the engaging-part opposing wall is configured to displace integrally with the urging part, and
• by the inner needle being pulled out of the outer needle hub, the block part engaged with the inner needle by the inner-needle engaging part is configured to move relative to the urging part to be in a state of non-contact, while the urging part is configured to displace in the direction of approaching the inner needle such that the needle tip of the inner needle is prevented from protruding from the safety mechanism part and engagement of the outer needle hub with the safety mechanism part is allowed to be released.