Patent ID: 7798993

Claim:
A syringe comprising: a barrel including an interior surface, a proximal end, a distal end, a fluid chamber and a tip at the distal end including an opening to allow fluid to pass therethrough; a plunger rod including a proximal portion having a proximal end with a flange adapted to accept a force applied from a user along a longitudinal centerline of the plunger rod and a distal end; a distal portion having a distal end with a stopper adapted to provide a slidable seal with the interior surface of the barrel; a breakable connection between the proximal portion and the distal portion adapted to break when the force applied by the user exceeds a breaking force, wherein the breaking force is greater than a force needed to expel fluid through the syringe tip during normal use; and means for reducing a contact impulse between the proximal and distal portions of the plunger rod when the breakable connection is broken, the means comprising a first surface on the plunger rod which contacts a second surface after breaking of the breakable connection, thereby reducing impact of the distal end of the proximal portion on the distal portion.