Abstract: This needle assembly is provided with a needle having a needle tip, a needle hub, and a protector. The protector is displaceable between a non-protection position at which the needle is exposed and a protection position at which the needle tip is covered; has an opening formed elongated to match the needle, and includes a main body and a claw-like portion. The needle enters the main body from the opening to cover the needle tip when the protector is displaced to the protection position. The claw-like portion is bent by the needle when the protector is displaced to the protection position, allows the needle to advance into the main body, and is elastically restored to lock the needle when the needle enters the main body. The claw-like portion projects obliquely from the main body, extends across the opening in the width direction, and extends in the longitudinal direction.

Abstract: This needle assembly is provided with a needle having a needle tip, a needle hub, and a protector. The protector is displaceable between a non-protection position at which the needle is exposed and a protection position at which the needle tip is covered; has an opening formed elongated to match the needle, and includes a main body and a claw-like portion. The needle enters the main body from the opening to cover the needle tip when the protector is displaced to the protection position. The claw-like portion is bent by the needle when the protector is displaced to the protection position, allows the needle to advance into the protector main body, and is elastically restored to lock the needle when the needle enters the main body. The claw-like portion projects obliquely from the main body, extends across the opening in the width direction, and extends in the longitudinal direction.

Abstract: In an indwelling needle assembly, a safety mechanism part is provided with an outer-needle-hub engaging part to be engaged with an outer needle hub, and an engaging-part opposing wall. Relative rotation of the outer-needle-hub engaging part and the engaging-part opposing wall is restricted, and at least one of the outer-needle-hub engaging part and the engaging-part opposing wall displaces integrally with urging parts. When an inner needle is pulled out of the outer needle hub, a block part engaged with the inner needle through an inner-needle engaging part is moved relative to the urging parts and forced to a non-contact state, and the urging parts displace in a direction approaching the inner needle, thereby preventing a needle tip of the inner needle from protruding from the safety mechanism part and releasing engagement of the outer needle hub with the safety mechanism part.

Abstract: In an indwelling needle assembly, a safety mechanism part is provided with an outer-needle-hub engaging part to be engaged with an outer needle hub, and an engaging-part opposing wall. Relative rotation of the outer-needle-hub engaging part and the engaging-part opposing wall is restricted, and at least one of the outer-needle-hub engaging part and the engaging-part opposing wall displaces integrally with urging parts. When an inner needle is pulled out of the outer needle hub, a block part engaged with the inner needle through an inner-needle engaging part is moved relative to the urging parts and forced to a non-contact state, and the urging parts displace in a direction approaching the inner needle, thereby preventing a needle tip of the inner needle from protruding from the safety mechanism part and releasing engagement of the outer needle hub with the safety mechanism part.