A NEEDLE ASSEMBLY (1) WITH A NEEDLE SHIELD (90,2110,90,10110) IS DISCLOSED. THE SHIELD INCLUDES A LUMEN (93,112,913,2112) SLIDABLE ON THE NEEDLE (10,210,510,910,1010), A CARRIER (16) AND NEEDLE BLOCKING OBJECT (3,102,122,922,2122,10122) WHICH MOVES AT LEAST PARTIALLY INTO THE LUMEN (93,112,913,2112) IN ORDER TO BLOCK DISTAL MOVEMENT OF THE NEEDLE (10,210,510,910,1010). A SPRING (2,110,111,911,2111) BIASES THE BLOCKING OBJECT (3,102, 122,922, 2122,10122) TOWARDS THE NEEDLE AXIS (11). PROXIMAL MOVEMENT OF THE NEEDLE (10,210,510,910,1010) RELATIVE TO THE SHIELD HOUSING(95,295,905) IS LIMITED BY A RESTRAINT (514)WHEN THE NOODLE SHIELD (90,2110,900,10110) MOVES FROM A NON-SHIELDING POSITION, THE NEEDLE BLOCKING OBJECT (3,102,122,922,2122,10122) MOVES AT LEAST AT LEAST PARTIALLY INTO THE LUMEN (93,112,913,2112) . THE NEEDLE BLOCKING OBJECT (3,102,122,922,2122,10122) IS RADIALLY AND AXIALLY CONSTRAINED IN THE SHIELDING POSITION. THE CARRIER (16) ALSO PREVENTS RADIAL, LONGITUDINAL AND CIRCUMFERENTIAL MOVEMENT OF THE BLOCKING OBJECT (3,102,122,922,2122,10122) . IN ONE EMBODIMENT, THE NEEDLE BLOCKING OBJECT (3,102,122,922,2122,10122) IS A BALL (3,122,21222). A CATHETER ADAPTER (52,282) AND TUBE (86,286) MAY BE THREADED OVER THE NEEDLE (10,210,510,910,1010). THE NEEDLE BLOCKING OBJECT (3,102,122,922,2122,10122) MAY ALSO LOCK THE CATHETER ADAPTER (52,282) TO THE NEEDLE SHIELD (90,2110,900,10110), ALLOWING IT TO BE RELEASED ONLY WHEN THE NEEDLE (10,210,510,910,1010) IS SHIELDED.
