LETTER-MARKING MACHINE. On the opposite page is illustrated an automatic letter-marking machine recently adopted by the Post-Office Department of the United States for use in the post-offices. The machine, which is manufactured by the International Postal Supply Co., of New York, under the patents of G. W. Hey, Emil Laass, M. J. Dolphin, and August Bertram, combines the merits of speed, effective cancellation, uniform and legible post-marking, and an accurate registry of the number of letters and postal-cards operated upon. Recent tests in the New York Post-Office show that upward of 40,000 pieces of mail matter have been successfully operated upon within one hour. It is therefore probably the most rapid printing machine known. All of the operations of the machine, after the letters are inserted in the receiving-hopper, are entirely automatic. The letters are placed in a receiving-hopper, as shown in the engraving, and are fed consecutively to the mechanism for applying the post-mark and cancellation, and recording device for indicating the number of letters operated upon, and are compactly packed in a stacking or delivery tray, after the marking and counting operations are effected.
The mechanism for performing the different operations of feeding, separating, marking.. recording the number of letters operated upon, and the final operation of stacking the letters, may be divided into three groups, namely, feeding and separating mechanism, the marking and counting mechanism, and the stacking mechanism. The feeding mechanism consists of a feed receptacle provided with a moving bottom, composed of an endless belt, which serves to carry the letters to a series of feeding and separating rolls arranged opposite to each other. The separating rolls rotate in the same direction relative to each other, so that their contiguous peripheries rotate in contrary directions ; one roller of each series being driven with greater speed and rotating in the direction of the feed, to carry the letters forward, while the oppositely arranged roller of the series rotates with less force and feeds backward the letter next to its face, if more than one at a time emerge from the letter receptacle. The reason why the
letters are consecutively presented by this feed is, that the roller which rotates in the direc tion of the travel of the letters is driven with greater speed and force than the conjointly acting roller arranged opposite to it. Hence the letter next to the roller, rotating in the direction of the travel, is carried forward with greater force than the letter lying next to it, which, if the two pass out of the feed receptacle together, encounters the reversely acting roller, and is therefore held back momentarily until the letter next to the feed-roller is carried past the reversely acting roller. It will thus be seen that but one letter at a time passes the separating rollers.
The marking mechanism consists of a curvilinear stamp secured to a stamp-roll loosely mounted on a rotating shaft so as to be normally at rest; this shaft carries a constantly rotating drum arranged to be engaged with the stationary stamp-roll by the action of a friction-clutch secured on top of the stamp-roll, and actuated by springs to expand when the clutch-jaws are released, and engage with the inner face of the constantly rotating drum when the clutch is operated by the contact of the letters with a trigger or pivoted lever, which lies in the letter-path, as the letters are presented to the marker by the action of the feed and separating mechanism.
The advancing end of the letter comes in contact with the tripping device in the letter path, and the movement, of the tripper releases the spring friction-clutch mounted on top of the stamp-roll, and the expansion of the clutch-jaws causes them to impinge the inner face of the rotating drum, thus connecting the stamp-roll with it, which is thereby caused to register on the moving letter.