Needle tip protector

An indwelling needle set comprising:

• an outer needle including a cannula and a housing body defining a chamber;
• an elastic valve supported within the chamber;
• an inner needle having a forward puncturing end and a rear end, the forward puncturing end having an enlarged diameter portion;
• and
• a needle tip protection device including:
• i) a needle tip protector body having a front portion configured to receive the rear end of the housing of the outer needle and a rear portion defining a rearwardly extending engagement tube defining a hole;
• ii) a stopper member supported within the rear portion of the needle tip protector body, the stopper member being movable from a first position obstructing the hole of the engagement tube to a second position providing access to the hole of the engagement tube;
• and
• iii) a protecting sleeve slidably positioned within the hole of the engagement tube between a first advanced position located substantially within the needle tip protector body and a retracted position extending rearwardly from the needle tip protector body through the hole of the engagement tube, the protecting sleeve having a forward end and a rear end, the rear end of the protecting sleeve being dimensioned to be slidably received in the hole of the engagement tube and the forward end of the protecting sleeve being dimensioned to prevent passage of the forward end of the protecting sleeve through the hole of the engagement tube,
• wherein the protecting sleeve defines a bore having a forward opening having a first diameter and a rear opening having a second diameter smaller than the first diameter, the inner needle being slidably positioned within the protecting sleeve, the enlarged diameter portion of the inner needle being greater in diameter than the second diameter of the rear opening of the protecting sleeve.