Safety shield for medical needles

A medical needle shield apparatus comprising:

• a shield extensible from a retracted position to an extended position, said shield including a cyndrical collar, a proximal segment articulating from said collar and an input link articulating from said collar, a distal segment articulating from said proximal segment and said input link, wherein said proximal segment includes a pair of axially extending arms that articulate from said collar and are connected to lateral portions of said distal segment,
• said collar defining an inner surface that defines a cavity, said inner surface including a plurality of radially inward projecting collar stops and said input link including an engagement surface that is engageable to urge said shield from said retracted position such that said input link and said proximal segment cooperate to extend said shield to said extended position, whereby said distal segment includes a nose portion that substantially encloses a distal end of a needle extending from a syringe;
• and
• a mounting ring configured for mounting to said syringe, said mounting ring having an outer surface that includes a plurality of radially outward projecting proximal stops and a plurality radially projecting distal stops, said collar being configured for relative rotational movement with said mounting ring such that said mounting ring is disposed in an interlocking orientation with said collar whereby said plurality of collar stops are disposed adjacent the outer surface of the mounting ring such that the plurality of proximal stops prevent distal axial movement, relative to a longitudinal axis of the syringe, of the collar and the plurality of distal stops prevent proximal axial movement of the collar.