Biopsy needle with completely closable cutting end bore

Claim 1

A biopsy needle for penetrating, severing and removing tissue specimens comprising: a hollow tubular needle body of racetrack cross-section, having a proximate hub end, and an open, distal end, said hollow tubular needle body being defined by laterally opposed, parallel straight walls integrally joined along opposite edges by respective, opposed arcuate walls, said distal end of said hollow tubular needle body terminating in an axially oblique, sharp cutting edge forming a pointed tip, at least the straight walls of said hollow tubular needle body narrowing toward each other at said body distal end to form a reduced lateral width bore, guide means provided within the hollow tubular needle body at the juncture between one arcuate wall and the opposed parallel straight walls, a thin flexible strip form metal, guillotine cutting blade of a width less than the distance between the opposed parallel straight body walls positioned between said guide means and said one arcuate wall for longitudinal sliding movement toward and away from said distal end, said flexible guillotine cutting blade having a width in excess of the distal end opening within said hollow tubular needle body such that said flexible guillotine cutting blade is prevented from projecting through said distal end opening, and is deflected toward said tip during sliding movement in a direction tending to close off said opening, said guillotine cutting blade terminating in a transverse curved leading edge conforming to the curvature of the hollow tubular needle body distal end other arcuate wall, and means carried by said blade to shift said blade between an axially projected position wherein said flexible guillotine cutting blade closes off said distal end opening and a retracted position where tubular needle body distal end is open to receive tissue to be severed.