The type u, are arranged on movable blocks marked 618, which are shown held in their retracted or normal position by springs 682, but when pressure is brought to bear against these type blocks in a direction outward from the sector, the spring 682 will give and the type blocks will slide outward in the slots provided to guide their action.
The paper, as will be noted, is fed from a roll, up between the type and the printing-roll 599, in the same manner as the paper of a typewriter, and through the interposition of an ink-ribbon between the type and the paper, the pressing of the type against the ink-ribbon, paper and roll gives imprint.
The pressure brought to bear on the type is through the hammer-blow of the printing-hammers 715, of which there is one for each ordinal printing sector. These hammers are pivoted to the rod 701, and are spring-actuated through the medium of the pin 741, the lever 716, and spring 780, which, combined with the cam-slot w, in the printing-hammers, serve to force the printing-hammers into the position shown in [Fig. 2].
The printing-hammers are normally retracted and latched by a series of trigger latches 117, through the latch-tooth b, which engages the lever 716 at v.
Each trigger-latch 117, is pivoted on the rod 700, and provided with an overlapping lug as shown in [Fig. 4]. These overlapping lugs, like those described on the trigger-latches in the Felt patent, serve as an automatic means of filling in the ciphers in the same manner as described in the Felt machine.
The means for tripping the overlapping trigger latches naturally differed from the means shown in the Felt machine, as the Burroughs machine was not key-driven.
A very ingenious means for the tripping of the trigger-latches is shown, consisting of the dogs 718, and rock-frame 711, and tie-rods 703-704, which co-operate with a cam-shoulder y on the arm of the printing-sectors, to remain neutral or to disengage the trigger-latches through a reciprocating action, shown in dotted lines in [Fig. 1, patent No. 505,078].
The tripping action takes place at the end of the forward motion of the actuating hand-crank through connections not shown in the drawings.
It may be understood that on account of the overlapping of the trigger-latches of the printing-hammers that if, as described in relation to the Felt recording-machine, one of the trigger-latches in any order to the left of the units order should be tripped, it would cause all the trigger-latches to the right to be also tripped, and the printing-hammers thus released to spring forward, giving an individual hammer-blow for each type impression.
Thus, if the five-hundred-dollar key should be depressed, only the trigger latch in that order need be tripped. This is brought about through the fact that normally the tripping-dogs 718 are held out of tripping engagement by the cam surface y of the type-sector, as the rock-frame in which the dogs are mounted is moved forward in its tripping action. But as the hundred-dollar order type-sector has been lifted through the setting of the (5) key in that order, it allows the tripping-dog to engage the trigger-latch of that order, and through the overlapping feature of the trigger-latches to trip and print the ciphers to the right.