Pellet length and end squareness inspection apparatus

Abstract

Apparatus for determining pellet length and end squareness which includes a base supporting a pair of linear variable differential transformers (LVDT) between which a pellet is placed for measuring end squareness. The LVDT's are perpendicularity detectors and each includes appropriate windings contained in a housing and an armature axially slidable therein. The armature is mounted on a shaft having extensions on opposite ends thereof. A swivel plate is attached to one end, while the other end is supported in a framework for the inspection apparatus, the arrangement being such that the housing containing the windings moves axially relative to the stationary armature. When a pellet is placed in position, each detector is advanced toward the pellet until its swivel plate contacts the pellet ends. If the pellet ends are not square, the swivel plates cock at an angle, thereby displacing the windings with respect to the armature. The relative displacement will be proportional to the tangent of the angle between the pellet ends and a plane perpendicular to the pellet axis. The pellet length is measured by a second LVDT which includes windings in a stationary housing. The armature moves relative to the windings and measures the relative distance between the swivel plates so that as the perpendicularity detectors sense the end squareness, the third LVDT senses pellet length along its axis. The output from the LVDTs is supplied to conventional readout circuitry and an indicating device which shows pellet length and end squareness.