摘要:
A device for selectively grasping a part of a separate elongated body extending through the device, includes at least three partially mobile jaw members defining between them a through hole of variable diameter depending on their mutual relative positioning, supporting and driving elements to which the jaw members are mounted and which are adapted to provide a coordinated motion to the members around the elongated body situated in the variable through hole, resulting in a closing or opening of the through hole. The jaw members have an elongated shape with two opposed ends and the supporting and driving elements include a circular or annular support body to which a first end of each jaw member is connected and a mobile annular driving body to which a second opposed end of each jaw member is connected.