The marking die or stamp is so placed on the stamp-roll as to commence its registry with the advent of the end of the advancing letter to the printing point, and an impression roll, yieldingly journaled so as to permit letters of different thicknesses to be operated upon, serves as an impression-bed for the letter while the stamp-roll is registering therewith.
After the die has registered, it is stopped by the encounter of a pawl pivoted to the trip, with a pin on the clutch, which encounter releases the die from engagement with the revolving drum : at the stone time an eccentric on the lower face of the stamp-roll is made to contact with a pro jecting stop, to prevent the stamp-roll from recoiling after the die has registered. The trip per, lying in the letter-path, is provided with springs which reset it immediately after the ad vancing end of the letter has passed the tripper, thus leaving the tripper in position for an other operation on a succeeding letter. and establishing the proper conditions for the release of the clutch from its engagement with the continuously rotating drum when the stamp-roll is stopped in proper position to register on the succeeding letter.
The marking-die is supplied with ink, through •the medium of a series of felt distributing rollers, the ink being provided from a rotating reservoir constructed with suitable vent-valves to regulate the flow of ink from the reservoir on to the felt distributors. Movable types are provided to change the date and hour of the post-marking die, and these consist of steel types set in a detachable radial-shaped type-box, which fits closely into an opening provided in the stamp-roll within the post-marking die, and the type-box is securely held in place by a spring which permits its release when it is desired to remove the same to change the date and hour.
The counting mechanism consists of a dial and indicator, and a series of synchronous toothed disks operated by a pinion-wheel, that, in turn. is actuated by the cam on 1 he stamp-roll disk, which. as it rotates, comes in contact with a crank-arm connected to the shaft operating the pinion-gear of the counter. As the stamp-roll rotates, the eccentric collides with the crank arm lying in the path of its movement, and motion is transmitted to the pinion so as 'to register one revolution of the stamp-roll on the indicating dial. and consequently mark the passage of one letter.
The stacking mechanism consists of a series of push-arms _radiating from a central hub carried on a rotating shaft arranged at right angles to the axis of the feed and printing-roller shafts, so as to feed the letters into a receiving-tray at right angles to the line of feed to the marking-stamp. The letters enter the delivery-tray through a pivoted chute arranged in
close proximity to the marking and pressure rolls, and are received between a series of robber faced rollers rotating within the chute, and a-re thereby fed down to the bottom of the delivery-tray against a sliding stop, and are propelled forward by the rotating push-arms before described. The delive•y-tray is inclined for the purpose of facilitating the packing of the letters as they are propelled forward by the push-arms. It will be observed that the marking-stamp rotates intermittently, invariably starting from a position at rest. when the tripper lying in the letter-path is moved by the advancing letter, and that the stamp-roll immediately stops after its registry with the letter, so that, no matter what the length of a letter may he, but one impression of the stamp is made on the letter in its passage between the marking and impression rolls ; and, since the stamp-roll is only brought into operation to ,register With a letter after the letter has encountered the tripper, there is no ink deposited upon the impression-roll, and " offsets " on the reverse face of the letter are avoided, so that the registration of the stamp-roll is absolutely controlled on each and every letter automati cally by the encounter of the letter with the stamp-tripper lying in the letter-path.
The principle or mode of operation upon which the marking mechanism depends is. that the letter itself controls its own marking by bringing the marker into operation to register thereon at the proper time and in the right place, and this principle is carried out in the mechanism by the arrangement of the parts as described, whereby the intermittent action of the marker permits the letter to receive the impression while in motion. All the devices are made adjustable, so that letters of indiscriminate sizes are readily operated upon, and, since there is no stoppage of the letter to make the impression, the speed or rapidity with which the machine performs its work is governed solely by the speed at which it is driven. In the post-offices a small electric motor from -I, to * horse-power affords ample power to drive the machine.
Link. Belts : see Belts.
Loader, Hay : see Ilay-Loader.
Lock-Cotter: see Barrel-Makiug Machines.
Locked Coil Rope: see Rope-Making Machines.