GB933568A - An automatic ribbon shift device - Google Patents

Abstract

933,568. Ink ribbon colour shift mechanisms. OLYMPIA WERKE A.G. Sept. 27, 1961 [Oct. 14, 1960], No. 34678/61. Class 100 (4). An automatic " black-red " ribbon shift mechanism in Fig. 1 for an electrically interlocked calculating-machine and a typewriter comprises two electromagnets 20 and 1, acting jointly on the ribbon shift mechanism, which are successively energized, on setting of a register " Sub " of the calculating- machine to subtraction, in such a manner, that a first hinged-armature magnet 20 lifts the actuating armature 5 of a second plunger-armature magnet 1 out of its " black " operational position and, at the same time through a make-contact 25 energizes the second magnet, whereby its actuating armature displaces the ribbon shift mechanism to the " red " position by linkage 8, 11. To set the shift mechanism in Fig. 1, into operation, when a negative sum is to be calculated, the switch " Sub " in Fig. 2 is closed, and the armature of the hinged magnet 20 is actuated via a change-over switch " U " and a normally closed break-contact " R " to close a retaining contact 24, the makecontact 25 and lift the actuating armature 5 into contact with a pin 7 of a lever 8, which is pivoted in an anticlockwise direction by the sliding movement of the actuating armature 5 of the energized plunger magnet 1, to impart a clockwise pivotal movement to a bell-crank lever 13 shifting an actuating bar (not shown) of the ribbon shift from a " black " into a " red " operating position. At the end of the sliding movement of the actuating armature 5 a projection 29 on the former strikes against the break-contact " R," whereupon the magnet 20 becomes de-energized, lowering the armature 5, which is returned to its normal position, indicated in Fig. 1, by the tension spring 27. When the printing in " red " has taken place the change-over switch " U " is changed over by a slider on a programme bar (not shown) and the plunger-armature magnet 1 becomes energized again to attract the actuating armature 5, now in its lower position, which strikes against a pin 6 of the lever 8 to thereby re-set the shift mechanism i.e. return the ribbon from " red " to a normally " black " printing position. The change-over switch " U " is then switched back de-energizing the magnet 1, and the actuating armature 5 is returned by the spring 27 to its normal position and the ribbon shift operation is terminated.