Two-coordinate length measuring device for microscopic instruments

Claim 1

A two-coordinate measuring device for use in the measuring ocular of a microscopic measuring instrument for measuring the dimensions of an object, said object having object axes (x and y coordinates), comprising: (a) two reference mark carriers, mounted movably with respect to each other in an intemediate image plane of said instrument, said reference mark carriers having the same path of movement and having a direction of movement which forms an angle of 45° with the object axes, said carriers each having a reference mark thereon, each reference mark comprising two perpendicular lines forming a 90° angle, with the two angles being oriented in opposite directions, such that the bisector of the angle of each of said reference marks coincides with the direction of movement of said carrier; and (b) means mounted in said measuring ocular for separately adjusting the position of each of said mark carriers in order to align said reference marks with the dimensions of said object, said object, said adjustment means comprising a pair of independently operable drive screws, mounted in said ocular at an angle of 45° with respect to the object axes, which engage said carriers, and means for the rapid setting of said drive screws, said rapid setting means comprising: (i) a cylinder solidly mounted on said ocular having a pair of oppositely disposed longitudinal holes therein; (ii) a circular nut which is slidable within said cylinder, and has a threaded central bore whose threads engage said drive screw, and at the end opposite said ocular, a pair of pins extending therefrom, said nut comprising an end section with a diameter corresponding to the internal diameter of said cylinder, an opposite end section of reduced diameter, and a ring section intermediate said end sections of smallest diameter; (iii) a pair of semi-circular clamping segments having a diameter corresponding to the internal diameter of said cylinder, each of said clamping segments having an activating button mounted exteriorly thereon which extends through the longitudinal holes in said cylinder, a shoulder portion which engages said nut and rests in said nut ring section, a bead on the outer surface thereof, a semi-circular depression on the interior surface thereof for passage of said drive screw, and a pair of transverse bores; and (iv) a pair of springs which are seated in the corresponding transverse bores of said clamping segments which bias said segments apart.