Carriage: The actuation and stopping of the longitudinal and cross feed of the carriage is done by handle 32, Figure 4-1. The direction of travel corresponds to the direction of the handle. The carriage travel during the threading operation is carried out by the leadscrew and half nut. Engaging of the half nut is made by handle 31. Figure 4-1. A protection is ensured between handle for starting of the automatic feeds and those for engaging of the half nut, which prevents simultaneous operations. The carriage functioning with the nut being engaged is made by using the handles 22, Figure 4-1. In addition to the feed mechanism, the carriage is equipped with a rapid traverse device. Actuation of the rapid traverse direction is selected by handle 32, Figure 4-1 for automatic feed. The button 41, Figure 4-2 is pressed for starting the rapid traverse motor. The carriage is equipped with an override clutch, which ensures the activation of the carriage rapid traverse with or without the feed box being engaged.