Device for coupling nuclear reactor control rods to drive linkage therefor and for maintaining control rods in reactor core

Claim 1

In combination, in a nuclear reactor, a guide tube traversible by liquid coolant, a nuclear reactor control rod displaceably received in said guide tube, a drive linkage and a device for coupling said nuclear reactor control rod, to said drive linkage and for uncoupling said control rod from said drive linkage comprising a bell-like coupling end formed on said drive linkage, said coupling end being provided with a pair of inwardly projecting nosepieces, a mushroom-shaped head formed on said control rod substantially matching the interior shape of said bell-like coupling end and being provided with at least two longitudinal slots for passing said nosepieces therethrough, said mushroom-shaped head being also formed on the underside thereof with staggered recesses disposed angularly to said underside and comprising stops for said nosepieces, entrainer means extending laterally from said control rod below said head thereof, substantially in a region through which said nosepieces are turnable relative to said control rod, and a plurality of peripherally spaced cams extending laterally from said control rod at at least one axial elevational position thereof, said guide tube being formed with recesses adapted to receive said laterally extending cams therein in a twisted locked position of said control rod when said control rod is in its lowermost position and said drive linkage is rotated to cause said nosepieces to abut said entrainer means and rotate said control rod.