626,148. Statistical apparatus ; transfer mechanism; zeroizing. THOMAS, A. Feb. 3, 1947, Nos. 3180 and 14237. [Class 106 (i)] In an accumulator including a plurality of denominational units, value entering means, transfer mechanism, total indicators and indicator actuating means, the transfer mechanism comprises a spur gear differential including a cage having a first sun-gear and a driving gear co-axial and rotatable therewith, a carry-over gear meshing with the driving gear, a pair of intermeshing planetary pinions carried by the cage and co-operating one with the first sungear and one with a second sun-gear co-axial with the first sun-gear, a train of reduction gearing of which the last gear is co-axial and rotatable with the second sun-gear and the first is connected with the carry-over gear of the next lower unit through a carry-over member movable angularly therewith, whereby when the second sun-gear is restrained against angular movement by its associated train of reduction gearing angular movement of the cage effects rotation of the driving gear, and angular movement of the second sun-gear due to operation of its associated train of reduction gearing increases the angular displacement of the driving gear to effect transfer. Transfer mechanism. Items sensed from perforated record cards are transferred to accumulator wheels by mechanism described in Specification 600,983. Each accumulator wheel (not shown) meshes with an idler gear 24, Fig. 5, which rotates a cage 25 comprising two intermeshing planet gears 43, 44. The first planet wheel 44 meshes with a sun-wheel 45 integral with a gear 29 which drives a carryover gear 30 and, through a gear 31, the indicator drum 32 ; the second planet gear 43 meshes with a sun-wheel 42 integral with a gear 41 which is driven, through gears 36, 40 from the carry-over gear 30 of the next lower denomination. Thus, rotation of the accumulator wheels is transmitted through trains of gears 24, 25, 44, 45, 29, 30, 31, to the indicator drums 32, and also through continuous gearing 24, 25, 44, 45, 29, 30, 37, 38, 36, 40, 41, 42, 43, 44, &c., with appropriate reduction, to higher denominations. To give them an apparent step-by-step motion, the indicator drums 32 are mounted on spindles 33, Fig. 7, rockable about a centre 35 under the influence of a bell-crank lever 53 which follows a stepped cam 51 rotating with the indicator drum of the next lower denomination. In this manner the fractional angular movements of an indicator drum arising from the continuous gearing transfer are hidden by contrary bodily movement of the drum relative to the observation aperture. When the transfer amounts to a whole unit the cam follower 52 drops down a step in the cam 51 and allows the drum to return and expose the next number. Zeroizing mechanism. The denominations of the accumulator are zeroized successively by a single clockwise movement of a handle 75, Fig. 8, secured to a gear-wheel 73 which rotates a pinion 72 on a shaft 71. The shaft 71 carries a series of pairs of discs 70, 76, each pair comprising a pin 77 and a corresponding notch whereby a Geneva-type of engagement with a member 64 is provided. The pins and notches of the various denominations are angularly staggered so that a pin 77 is just entering a slot 78 when the member 64 of the next lower denomination has just completed its rapid, clockwise zeroizing movement which, through linkage 63, 62, rocks an arm 57 bearing a spring-urged pawl 59 a predetermined amount so that one of the pins 56 on the carry-over gear 30 is carried by the pawl 59 to a position corresponding to zero on the indicator drum 32. Overthrow is prevented by the engagement of a projection 79 with the teeth of the gear 30. To prevent operation of the zeroizing mechanism during an accumulating operation, a slidable link 80, connected to the gear 73, comprises a pin 86 which rides on the edge of a disc 84 fixed to the mainshaft 15. Thus, the handle 75 can be moved down only when a notch 85 comes opposite the pin 86. Moreover, the sloping edge 87 of the notch forces the pin 86 upwards if the disc commences to rotate while the handle 75 is down. In a second embodiment a cam 115, Fig. 10, is mounted at each end of the spindle 71 carrying the Geneva discs 70, 76, and as the spindle commences to rotate, levers 117 connected by an angle bar 119 are rocked backwards pulling, through a linkage 121, 105, toothed elements 104 into engagement with gears 103 fixed to the idlers 24. Meanwhile, through linkages 63, 62a, levers 57a are successively rocked clockwise and, in each case, a pawl 59a engages one of a number of pins 56 and moves it to a position representing zero, overthrow being prevented by a spring-urged detent 110 engaging one of the pins 56. Instead of indicator drums, vertically-slidable strips 100 are marked with numerals observable through an aperture 128, but are operated only during the zeroizing operation when the toothed elements 104 are brought into engagement with the gears 103. A linkage 106, 107 connects each element 104 with its corresponding indicator strip 100. The invention may be applied to the direct-carry type of transfer mechanism by employing a face cam 250 (Fig. 14, not shown), co-operating with a contrate gear-wheel which takes the place of the gear 41, Fig. 5.