Abstract: A movable automatic bolt driving apparatus sequentially drives a plurality of bolts positioned substantially in line on flanges of elongated concrete molding frame segments for producing columnar concrete products. The apparatus has a vertically movable bolt driver unit and an air-cylinder unit. When the bolt driver unit drives a bolt in a state that the socket and the bolt are non-concentrically engaged with each other, the air-cylinder unit causes to properly reposition the bolt driver unit. At least a part of the bolt driver unit, which is normally disposed vertically, is pivotable with a horizontal pivotal axis orthogonal to the moving direction of the apparatus. The apparatus also has a flange follower for guiding the bolt driver unit. At least a part of the flange follower, which includes a roller having a vertical rotating axis, is pivotable about a vertical rotational axis.

Abstract: There is provided a socket mechanism for rotating a bolt or nut, or like fastening piece, that is used with a vertical type powered bolt/nut driving apparatus. The socket mechanism has a spindle that can be coupled to a drive shaft of the driving apparatus, a socket for engaging with the bolt or nut having a guide at the bottom end thereof for facilitating the object bolt or nut to slip into the socket, a socket holding core having a downwardly tapered mid section, and a generally cylindrically-shaped core holder fixedly attached to the spindle having a bottom opening. The socket is fixedly attached to the low end of the socket holding core. The tapered part of the socket holding core freely lies on the rim of the bottom opening of the core holder in a manner that a lower part of the core and the socket are below the opening and suspending from the core holder.