Letterpress printing press

A letter press printing press including at least one pressure element, an ink ribbon and a pressure absorption plate arranged in vertical sequence, an interchangeable form carrying printing indicia positioned between the ink ribbon and the pressure absorption plate, and a sheet to be printed positioned between the pressure element and the ink ribbon in which all of the elements are pressed together by said at least one pressure element and the pressure is absorbed by the pressure absorption plate, comprising a delivery spool and a wind-up spool disposed at a corresponding distance from one side of the pressure absorption plate, the pressure absorption plate having two free edges extending longitudinally of the press, a cassette housing, said delivery spool and wind-up spool having spool rotation axes mounting said spools in said cassette housing, said ink ribbon wound on said spools, said cassette housing including guide means which guide the ink ribbon in the press from said delivery spool about one said free edge of the pressure absorption plate adjacent to the same, transversely across the pressure absorption plate in spaced relation thereto, transversely about the other said free edge of the pressure absorption plate and to said wind-up spool, said cassette being removable from and insertable in the press parallel to the spool rotation axes, the said spool rotation axes project from the cassette housing at least at the end at which the cassette is removable from the press, said press including a cover having a depending rib having slots therein, said spool rotation axes inserted through the slots in said depending rib, said cover disposed parallel to the pressure absorption plate and hinged to permit the cassette to be changed and the direction of rotation of the said spool rotation axes during transport of the ink ribbon being such that the spool rotation axes are pressed inwardly against the ends of the slots.

A letter press printing press including at least one pressure element, an ink ribbon and a pressure absorption plate arranged in vertical sequence, an interchangeable form carrying printing indicia positioned between the ink ribbon and the pressure absorption plate, and a sheet to be printed positioned between the pressure element and the ink ribbon in which all of the elements are pressed together by said at least one pressure element and the pressure is absorbed by the pressure absorption plate, comprising a delivery spool and a wind-up spool disposed at a corresponding distance from one side of the pressure absorption plate, the pressure absorption plate having two free edges extending longitudinally of the press, a cassette housing, said delivery spool and wind-up spool having spool rotation axes mounting said spools in said cassette housing, said ink ribbon wound on said spools, said cassette housing including guide means which guide the ink ribbon in the press from said delivery spool about one said free edge of the pressure absorption plate adjacent to the same, transversely across the pressure absorption plate in spaced relation thereto, transversely about the other said free edge of the pressure absorption plate and to said wind-up spool, said cassette being removable from and insertable in the press parallel to the said spool rotation axes, separate flange elements disposed coaxially on the spool rotation axis of said delivery spool on each side of the ink ribbon wound thereon, one of said flange elements fixedly mounted on said delivery spool rotation axis and the other of said flange elements being longitudinally displaceably mounted thereon, said cassette housing having an end face, the longitudinally displaceable flange element disposed in contact with said end face, means coupled to said delivery spool rotation axis to spring bias it in the axial direction from the fixed flange element toward the displacement flange element such that the ink ribbon wound on said delivery spool normally maintains the separate flange elements spaced apart from one another and when the ink ribbon has been completely unwound axially moves the fixed flange element with the delivery spool rotation axis toward the longitudinally displaceable flange element and indicator means coupled with said means spring biasing the delivery spool rotations axis and releasable upon such axially movement thereof to indicate that the cassette housing should be changed.