Lubricator with channel which communicates reservoir with oil drop hole

A lubricator comprising:

• an oil cup opened upwardly;
• a cover through which an air conduit including an orifice extends substantially in a horizontal direction and which is received on upper side of said oil cup;
• a supply hole formed in upper side of said cover and extending to said orifice;
• a transparent oil drop cylinder including a drop hole extending through an upper side thereof and mounted on said cover so as to overlay said supply hole;
• a transparent adjusting cap adapted to be fit around said oil drop cylinder and integrally provided with a needle valve downwardly projecting from a center of the upper side in alignment with said drop hole, said cap being adjustable axially of said oil drop cylinder in order to control an aperture of said drop hole;
• and
• an air-tight channel adapted to communicate an oil reservoir within said oil cup with said drop hole through a space defined between an upper surface of said oil drop cylinder and said adjusting cap;
• wherein a pressure differential produced between a pressure acting upon the oil surface within said oil cup and a pressure within said orifice provides a suction effect under which a quantity of oil within said oil cup flows through said channel to said space defined between an upper surface of said oil drop cylinder, then drops through said drop hole into said oil drop cylinder and is finally atomized through said supply hole into the air stream flowing through said orifice.