Part 18

Now such simultaneous key-action as had been invented and used on cash registers was not designed with the thought of increasing the speed of manipulation in such machines. The simultaneity of the cash register was designed to compel the operator to depress the keys, which represented the amount of the purchase, exactly simultaneous; otherwise, by manipulation the proper registration could be made to show on the sight-register and a short amount on the total-register. It was a device to keep the clerk or salesman straight and prevent dishonesty.

If you have ever watched an expert operator using a “Comptometer,” try to imagine that operator hesitating to select a group of keys and depressing them exactly simultaneously as one is compelled to do on one of the key-driven cash registers. And then, on the other hand, if you have ever seen a key-driven cash register operated, try to imagine its being operated at the lightning speed at which the “Comptometer” is operated.

In making this comparison, the reader should be careful not to confuse the later key-set crank-driven type like that of Pottin described in the preceding chapter. It was the old key-driven type of cash register which contained the forced simultaneity of key-action.

It must be understood that the exact or forced simultaneity of the cash register scheme, if applied to a calculating machine, would lock the whole keyboard if one of any of a group of keys the operator wished to strike was depressed ahead of the others, and would thus prevent the rest of the group from being depressed until the return of the first key.

It is within reason that a locking action of that character would even defeat the speed of key-action that was possible on the old “Comptometer,” since an operator could overlap the key strokes in that machine to a certain extent; whereas the forced simultaneity of the cash register, if applied to the “Comptometer,” would prevent any overlapping or the depression of a second key until the first depressed key returned.

The only simultaneity of key-action that could provide a means of speeding up the old “Comptometer,” or any machine of its type, was a means that would leave key-depression free as to matter of time; one that would be perfectly flexible in group manipulation, offering a complete fluidity of motion such as not to hinder the fingering of the operator.

The purpose of the mechanical means employed to give simultaneity in the cash register was to lock all the keys depressed together and lock all others against depression until the former returned. The purpose of mechanical means employed in the Felt patent was to give perfect freedom of key-action, whereas formerly the key manipulation of the old “Comptometer” was restricted in the freedom of key-action, to the extent of being limited to seriatum action.

The above discussion has been somewhat elaborately detailed to offset statements that simultaneity was old in the key-driven Art. There is no question as to the cash register type of inflexible simultaneity of action being old before Felt patented his flexible type of simultaneity of key-action for a key-driven calculating machine; but any statement intended to convey the idea that Felt’s contribution of the flexible simultaneity of key-action to the Art was not new, must come from ignorance of the facts or malice aforethought.

This flexible keyboard “Comptometer” was given the trade name of “Duplex Comptometer;” the term “Duplex” meaning that two keys could be depressed, as distinguished from the seriatum one at a time key-action formerly required. The term, however, fell short of setting forth the capacity of such action, as it was, in fact, not restricted to mere duplex-action--it was really a multiplex key-action having no limit except the lack of fingers on the part of the operator to depress the keys.

The validity of these patents has been sustained in litigation. The technical scope of the mere claims has been disputed, as patent claims sometimes are; but the broad newness and importance of the practical calculative capacity achieved is beyond dispute. The recent machine called the “Burroughs Calculator” has multiplex key-action, but it did nothing to advance the practical capacity of key-driven calculating machines.

The operation of key-driven machines has always been attended more or less with a feeling that a key-stroke may not have been completed, especially by a novice in operating. Recognition of the possibility of errors occurring through incomplete key-strokes in key-driven adding mechanism was first disclosed as early as 1872 in the Robjohn patent (see page 36), in which a full-stroke device is shown co-acting with the keys.

In the drawings it will be noted that for each key there is provided a ratchet device co-operating with the key to compel a full-stroke. This scheme, like other similar later attempts, was aimed at the prevention of an error in the operation of adding mechanism, but as a means of prevention of an error it was lacking, because unless the operator noticed that the key had not returned the next key depressed would, through the action of the rotor, pull the partly depressed key way down until it was released, when it would rise again, possibly without the knowledge of the operator. There still remained the fact that the occurrence of the error was not made known to the operator until it was too late to correct it.

That Felt was interested in the solution of the problem for detection and correction of the errors in key-strokes is shown in the several patents issued to him on features pertaining to this subject. After numerous experiments Felt came to the conclusion that it was futile to lock a key in event of a partial stroke and that the solution lay in the locking of the keys in the other orders from that in which the error had been made, thus signaling the operator and compelling correction before further manipulation could be accomplished.

Again we find, as with the simultaneity of key-action, that a question may be raised as to the novelty of invention by those who wish to say that there are full-stroke mechanisms in the key-driven cash register Art that lock the rest of the keyboard. But the key-locks disclosed in the cash register were directed to a continuity of stroke engroup, as distinguished from the individualism necessary to the key-driven calculator.

The mechanical means employed, of course, varied greatly from that which would be of any value in the calculating machine Art, and the theoretical scheme was aimed at a widely different result. Flexibility was necessary.

The feature sought by Felt for his calculator was a signal to the operator that an error had been made--if an error should occur--and to block the operation of any of the other orders until the error was corrected. This he accomplished by causing all the other orders to be locked against manipulation, through the occurrence of an error in a key-stroke; thus preventing manipulation of another order until the error was corrected.

Now it may be said that the locking of other orders was old in the cash register; but let us analyze the scheme and action of both. The depression of a key of the key-driven cash register immediately locked all other keys not depressed, and retained such locking-action during depression and until the complete return of such key-depression; thus the keyboard was locked, error or no error.

A correct depression of a key in Felt’s new invention, as applied to key-driven calculators, does not lock the rest of the keys. In fact, no key of Felt’s invention is locked until an error occurs.

The lock of the key-driven cash register is a lock that takes effect without an error having occurred--one that is always present with respect to the keys not depressed simultaneously, and a feature designed to force simultaneity of group key-action to prevent, as before explained, dishonesty.

The lock of the key-driven calculator inventions referred to are in no way connected with simultaneous key-action--as in the cash register--and never act to lock the other orders except when there is an error in a key-stroke. As the writer has explained respecting the simultaneous feature of the cash register, the locking of the other orders in the cash register interfered with the flexibility of the key-action and for that reason would be impossible in a key-driven calculator, where rapid manipulation is dependent on flexibility.

The scheme of the new key-driven calculator inventions referred to, were designed to allow perfect freedom of individual key-action and to block such action only when an error in any individual key-stroke should be made. There is nothing in common in the two schemes. The time, purpose and mechanical means employed differ entirely.

This new idea of Felt’s is embodied in what is commercially known as the “Controlled-key Duplex Comptometer.” The term “Controlled-key” was coined to fit this broadly new combination, but a word coined to fit the functions of a new mechanism is seldom enough to convey a complete understanding of its true qualities.

Aside from the broad newness of the Felt “Controlled-key” feature referred to, even the mechanical means for safeguarding the individual key-action was new in its application as a full-stroke device. The means employed operated directly on the accumulator mechanism, locking it against registration until the error was corrected, which differed greatly from the devices applied to the keys or actuators designed by others to bring about a similar result. But the locking of all the other orders of mechanism, through any key-action short of a full stroke, as a signal or error, has no mechanical equivalent or simile in the Art.

The Improved Recorder

Since the general installation of the recording-adder by the banks, the minds of “get-rich-quick” inventors have been turned toward this type of machine. The result has been that a vast number of patents on such machines were issued, a large proportion of which represent worthless and impossible mechanism purported by their inventors to contain improvements on the Art. Some of these patents on alleged improvements describe and purport to contain features, that, if really made operative in an operative machine, would be useful to the public. But as inventions, they merely illustrate the conceptions of a new and useful feature that can never be of use to anyone until put into concrete operative form.

To describe these features would be useless, as they have not advanced the Art; they merely act to retard its advancement through the patent rights that are granted on the hatched-up inoperative devices or mechanism purported to hold such features.

Of the vast number of patents issued, but few of the machines represented therein have ever reached the market, and of these machines, except those previously mentioned, there is little that may be said respecting new elementary features that may be called an advancement of the Art. It is to be expected, of course, that the manufacturer of such machines will not hold the same opinion as the writer on this subject. But the fact that the generic principles of recording the items and totals were worked out before they even thought of constructing such a machine leaves little chance for anything but specific features of construction for them to make that may be considered new.

Another feature to be considered in this line is that while these new manufacturers were working out the “kinks” or fine adjustments, which can only be determined after a considerable number of machines have been put into service, the older manufacturers were working or had worked out and held in reserve new improvements that were not obvious to those new at the game.