Abstract: A railway car for transportation of motor vehicles. The railway car may be articulated, comprising two or more units. The railway car may have end doors which are pivotally attached to the roof of the railway car. Flexible seals may be provided along the inner and outer edges of the end doors. Ventilation in the side walls of the railway car may be provided by small diameter perforations grouped at elevations near the top and bottom of each level. The side walls may be constructed by a combination of load bearing side wall panels which function as shear plates, and vertical posts. Protection for the door edges of motor vehicles being carried in the railway car may be provided by providing a plurality of parallel horizontal strips of a relatively soft material along the inside of each side wall on each level. A flexible enclosure may be provided between adjacent car units. A heat-reflecting corrosion-resistant coating may be provided on the galvanized steel corrugated roof to extend the life of the roof.

Abstract: A threaded ball screw is stationarily non-rotatably mounted in a machine tool to extend parallel to the line of action traversed by a carriage. A pair of threaded ball nuts are laterally restrained in and mounted for free rotation thereof in a drive mechanism of the carriage and threadably and concentrically engage the ball screw in laterally spaced apart co-axial relationship therealong. A pair of digitally controlled electric drive motors are mounted in the carriage for individually imparting rotational torque to the nuts. A conventional programmably CNC controller is programmed to synchronously control both motors for causing the ball nuts to conjointly produce computer controlled linear motion and positioning of the carriage along the stationary ball screw, and to develop anti-backlash pre-load forces between the ball nuts relative to the ball screw.