The spiral automatic does away with the channel entrance stopping bar and flexible entrance partitions. The channel entrances of the new style are equipped with fixed partitions which can not become bent, damaged or twisted out of adjustment by the action of the distributing mechanism. Some of the features are: The channel entrance partitions are thinner, allowing large matrices to pass freely through the channels. The partitions are more rigid, although thinner, because they are fixed and supported their entire length. The entrance once set, does not have to be readjusted for different sizes of matrices.
The partitions have guides at their lower end, which are arranged to direct the various matrices into their respective channels by having contact with the lugs instead of the body of the matrix, giving the minimum amount of friction.
Two rotary wedges are pinned to the right end of the two front distributor screw shafts. These wedges are placed so the thin edge of one wedge is opposite the thick edge of the other. These wedges rotate with the screws.
The small timing gear on the lower front distributor screw is loose on the shaft. A connection between the screw and the gear is made by two parallel pins, one on the gear and the other on the wedge. These pins are held together by a spiral spring. The tension of the spring should be so the slightest drag on the lower screw would allow the pins to separate.
When anything binds or retards the revolution of the lower screw, the two parallel pins separate, which changes the relation of the wedges, causing them to lock. This locking of the wedges stops the distributor screws and releases the tension of the clutch flange on the distributor washer clutch flange permitting the driving pulley to run free.
Assembled on the distributor clutch pulley washer clutch flange are two distributor clutch stops. These are called left-hand stops. Fastened to the distributor clutch flange are two distributor clutch stops. These are called right-hand stops.
When the distributor is operating, the right-hand stops are held on the left-hand stops by two spiral springs. One end of each spring is fastened to an adjustable spring collar that slips over the distributor clutch flange; the other ends are fastened to the pulley washer clutch flange. These stops force the pulley washer flange against the driving pulley, operating the distributor.
The tension of these spiral springs should be just tight enough to hold the stops together. When the spiral locks, the tension of the spring should permit the right stops to leave the left, releasing the pressure on the driving pulley.
The tension of these springs can be adjusted by releasing the clamping screw in the spring collar and turning the collar.
Remember that anything binding the lower screw will prevent the distributor from operating.