Blood sampling instrument

Claim 1

A blood sampling instrument designed to be hand held by an operator and being adapted to prick a finger or the like of a patient to draw a few drops of blood, said instrument having a distal end toward a patient and a proximal end toward an operator, comprising in combination: (a) a tubular member having a hollow nosepiece at the distal end with an aperture at the terminal end thereof and a spring chamber at the proximal end, (b) an annular collar having a shoulder at the proximal end thereof and an annular flange immediately behind said nosepiece at the distal end of said collar, (c) a hollow sleeve surrounding said spring chamber, (d) a plunger mounted for reciprocation within said tubular member, (e) a shoulder within said tubular member, a main spring mounted within said spring chamber, said shoulder engaging said spring and biasing said plunger toward said nosepiece, (f) a socket and a needle mounted therein on the distal end of said plunger, (g) an aperture on the side of said tubular member, a finger on said plunger to engage said aperture and hold said plunger when said plunger is drawn away from said nosepiece, (h) a trigger button extending from said collar and having means to engage the finger on said plunger, (i) plunger cocking means on said sleeve to pull said plunger away from said nosepiece and engage said finger whereby (j) the nosepiece of said instrument can be pressed against a finger by exerting pressure on said flange while pressing said trigger to release said plunger and cause said needle to be driven out of said nosepiece.