223,301. Haddan, R., (National Cash Register Co.). July 17, 1923. Machines with several item-value totalizers, the engagement of which with the differential actuating mechanism is controlled mechanically by means superposed upon and over-riding the keyboard control, as in Specifications 191,350 and 203,995. The mechanical means in this invention comprise a number of notched plates 82 set differentially by the special keybanks and controlling a number of multi-pronged pawls 86 interposed in the totalizer-engaging mechanism. When the plates occupy positions such that the presence of a notch or notches permits the pawl under the influence of a spring to move towards the plates, the corresponding totalizer line cannot be engaged. The pawls may be replaced by others having their prongs differently arranged in order to vary the control. In the form shown, the pawls 86, three in number corresponding with the three lines of totalizers, have two prongs engaging the first and third notched plates or discs 82 and an oppositely-extending prong to engage the second plate. These plates are differentially positioned under the control respectively of a clerk's bank, the transaction bank and a second clerk's bank, and the three pawls control the engagement of the three lines of totalizers assigned respectively to the three banks of control keys. The totalizer lines are moved in to engage with the actuators by means of links 110, Fig. 5, provided with pins 109 adapted to be embraced by the hooked arms 108 of a spider plate 107. This plate is rocked clockwise by cams 88, 90 on the main shaft 30, and if a pin 109 occupies the position shown in Fig. 5 the link 110 will be drawn along and the selected totalizer engaged. The pins 109 are, however, also controlled by a slotted arm 119, Fig. 6, embracing a pin 118 on the link 110 and pivoted to a plate 121 rocked clockwise and then counterclockwise from a cam 123 through link 128 and three-armed lever 130. The pawl 86 is mounted at 131 upon this arm 119, and the arrangement is such that, provided obstacles to the movement of the pawl 86 towards the centre 84 are offered by the peripheries of the plates 82, the counterclockwise rocking of plate 121 causes arm 119 to swing about pivot 131 and thus move pin 109 into the embrace of arm 108, so that the corresponding totalizer line will be shifted into engagement. If, however, the first and third plates 82 both present notches to the two prongs of a pawl 86, or the second plate presents a notch to the single prong, then the pawl is free to move inwardly and the arm 119 merely rocks about pin 118, so that pin 109 is not shifted into effective position and the totalizer line remains disengaged. Specification 8119/15 also is referred to.