The tip protector (30) for the safety catheter (10) includes an outer member releasably engaging the inner cavity of the catheter hub (16). The outer member (34) comprises protrusions (127, 134) secured radially outwardly to exert a holding force and an inner member (32) axially received in the outer member (34). The needle cannula (22) is housed within the inner member (32) and the outer member (34) and has a distal position in which the distal end (24) extends in the distal direction of the tip protector (30) and a distal end (32) can be axially displaced between a proximal position in which the inner member (24) is located within the outer member (34). Regardless of the position of the inner member (32) between the distal and proximal positions, the retention force of the outer member (34) against the inner wall of the catheter hub (16) is kept substantially constant(FIG.安全カテーテル（１０）用の先端保護具（３０）は、カテーテルハブ（１６）の内側キャビティと解放可能に係合する外側部材を含む。外側部材（３４）は、半径方向外側に固定されて保持力を作用させる突出部（１２７、１３４）および外側部材（３４）内にて軸線方向に収容される内側部材（３２）を備える。針カニューレ（２２）は、内側部材（３２）および外側部材（３４）内に収容され、遠位端（２４）が先端保護具（３０）の遠位方向に延びる遠位位置と、遠位端（２４）が外側部材（３４）内に位置する近位位置との間で、内側部材（３２）を軸線方向に変位させることができる。遠位位置および近位位置の間における内側部材（３２）の位置に関わらず、カテーテルハブ（１６）の内壁に対する外側部材（３４）の保持力は実質的に一定に保たれる【選択図】図１
