Abstract: An imprinter particularly for credit cards, includes a printing bed, a support secured to one end of the printing bed and two spaced guide frames turnably supported on the support and provided with elongated guide grooves receiving rollers of a carriage supporting a printing roller. The carriage is turnable together with the guide frames between an operative position in which the carriage is on the printing bed and an inoperative position in which the carriage is away from the printing bed. The support includes two portions bent downwardly and spaced from each other and each being provided with an inclined edge and a vertical edge. A transverse shaft mounted between guide frames engages with the vertical edges of the respective portions of the support to lock the frames and the carriage in the operative position.