Apparatus for injecting a desired volume of liquid in liquid and gas-liquid chromatography

An apparatus for injecting a desired volume of a liquid in liquid and gas-liquid chromatography comprising:

• a tubular holder defining a lengthwise recess in a wall of an upper part, a cylindrical shell-shaped cover extending over the upper part;
• a syringe positioned within said holder comprising, a needle joined to said syringe protruding outwardly from one end of said holder, a plunger head movable inside said holder longitudinally, said head having pins and guide knobs extending therefrom and a capacity scale formed in a side surface of said syringe;
• driving means positioned within said holder behind said plunger, said driving means including a push piece lying in contact with said plunger head said push piece having a protuberant pin, guide knobs, and guide knob pins attached to said push piece and a spring inserted between said push piece and the other end of said holder;
• a window formed in a side surface of the part of said holder containing said syringe so as to read said capacity scale of said syringe;
• first slots formed in side surfaces of said holder, said guide knobs protruding from sides of said push piece and said plunger head through said first slots;
• a start button disposed at one end of said recess;
• a lever arranged in said recess a portion of which is held in contact with said start button;
• and
• a mechanism locking said push piece in an urged position and including a flat spring arranged in contact with the other end of said lever in said recess and an hole provided in a flat portion of said flat spring and engaging with said protuberant pin of said push piece.