The mechanism of this machine is not illustrated in any one patent. The Felt patents Nos. 441,233 and 465,255 cover the new feature, but the later patent, No. 465,255, shows it best. Some of the drawings of the last-named patent are [reproduced on the opposite page] to help in explanation of the details of the new features.
Description of Felt’s second recorder
By referring to the [drawings], it will be noted that the form of the front of the casing differs from the machine. Other drawings of the patent, not shown here, disclose features of still later invention than were in the machine of the [photo reproduction]. But it is with the printing device that we are now interested, and it was in this patent that it was first shown in the form used in the first marketed machine referred to.
The type sector marked 81 is like that of the first patent, except that it is provided with the ciphers as well as the nine digits.
The cipher type are always presented for printing when the sectors are resting at normal. Thus, if an impression can be made without depressing the keys in that order, a cipher will be printed, as will be shown later.
Back of the paper and pivoted to the rod 97, are a series of printing hammers 87, one for each type sector.
The hammers are operated by the spring 88, and are shown retained against the tension of their springs by the trigger latches 89.
These trigger latches are pivoted on the fixed shaft 171ᵃ, and actuated by the springs 92 to cause their engagement with the notch 90 of the printing hammers.
From Drawings of Felt Patent No. 465,255