Rocking Segment Mechanism (page 5)
Subjects
- functions keys
- printing optimization
On this page I like to point to a few remarkable site mechanisms who contribute as well to the rocking segment machines performances.
Printing mechanism optimization
As you have seen earlier on in this chapter, both gears of the rocking segment technology have to grip in each other for proper operation. This makes the gears rather heavy and thick. Although placed forks put the rocking segment in line, the gears have to be rather thick.
Later machines used a third gear wheel, which is a few millimeters thick, and forms the gear between the original two rocking segment gears. Those can be much thinner now.
Manufacturer
Walther use this principle in their printing section. The circular printing heads have teeth on the opposite of the number stamps. That gear part, of the printing head, is pushing to such an intermediate gear, which is rolling on a horizontal flat gear rack. Further on this rack the registers are placed. There are two register racks, one for the positive result printing and one is put on the gear rack for results who are below zero. (Please see the part on the nylon gears further on)
Here the circular printing heads are shown. In front of those the intermediate gears are placed. The horizontal gear rack is seen below. There is a bar above the intermediate gears to keep them in position, when needed.
The situation for just one digit is showed on the picture to the left. When the actual printing is taking place the whole printing head is pulled of the intermediate gear and pushed to the paper. Due to the lower mass, this can executed at an extreme vast speed (< 0,1 sec.).
The two registers of the Walther Comptess are made of nylon. This is showing the time where these are made. And after many years of usage no wear-out is seen.
The two gear racks, instead of one are used to avoid nine complements notation of the result when the result is below zero.
The function keys on the key board
We have key boards until now not divided into groups of keys. I mean the "numerical input keys" (left on the key board picture below) and the "function- or special action keys" like add, subtract, total print, sub total print, multiply etc. (right on the picture). When your pushing keys of both groups, you will notice immediately the difference.
Pushing a numerical key will extend a pin in a column below the keys. This pushes a in in the pin block and shift the pin block to the next position. On the bottom side key board picture (below right) you see in the middle a column of holes. Every numerical key has it's own pin in the column.
An action key starts a machine cycle. You probably notice the number of levers coming out of the key board (top of the pictures). By manual machines starts the action, of course after operation of the crank. By electric motor driven machines the action is immediately executed after activate the function key.