This creation has a protective sleeve,In order to provide a cylinder with freedom of axial rotation and sliding,The protection sleeve comprises a clamp fixed position section and a ring-shaped convex part of a release positioning section；A locating clip which is connected to the cylinder and has a pressing part and a fixing part,The fixing part is positioned to fix the annular convex fastener,When the protective sleeve rotates to make the release locating section correspond to the locating clip,And press the pressing part,The clamping part is swung from an initial position to an actuation position,The annular convex part is separated from the positioning and fixation of the fixation part.Therefore, the user needs to meet the above two operating conditions at the same time, so that the protective sleeve can be moved out and the injection head can be covered, so as to effectively solve the problem of misoperation caused by MIS touching the pressing part.本創作為具有一保護套筒，為供一筒體套入且具有軸向轉動與滑移之自由度，該保護套筒包含具有一卡固定位段以及一釋放定位段的一環狀凸固件；一連接於該筒體且具有一按壓部與一卡固部的定位扣夾，該卡固部定位卡固該環狀凸固件，當該保護套筒透過旋轉而使該釋放定位段對應至該定位扣夾，且按壓該按壓部，使該卡固部由一初始位置擺動至一作動位置，讓該環狀凸固件脫離該卡固部之定位卡固。據此使用者需要同時滿足上述兩種動作的條件，才能使該保護套筒外移而罩覆注射頭，有效解決誤觸該按壓部所造成之誤動作問題。
