Micrometric dispenser with calibration means

Claim 1

A micrometric dispenser comprising a cylinder having an open end for liquid intake and delivery and an opposite open operating end, a flanged member detachably secured In place and closing said operating end, said flanged member having an opening therethrough and comprising an indicia carrying part, a piston rod slidable through said opening, a piston carried by said piston rod and sealingly slidable along the inside of said cylinder, first stop means on said piston rod effective to limit the degree to which said piston rod can be slid out from said cylinder, second stop means on said piston rod outside said cylinder effective to circumferentially rotate about said indicia carrying part of said flanged member and engage said flange on said flanged member to limit the degree to which said piston rod can slide into said cylinder, said stop means being adjustably positionable along the length of said piston rod, thereby to adjustably vary the degree to which said piston rod may be reciprocated relative to said cylinder, and cooperating indicia present, respectively, on said indicia carrying part of said flanged member and said second stop means calibrated to indicate the degree of reciprocal motion permitted said piston rod, a reference line on the indicia carried by said flanged member extending on said flanged member to a point outside said second stop means when said second stop means engages said flange on said flanged member whereby said reference line and the indicia carried by said second stop means cooperate to define the zero starting point of said dispenser.