[Illustration: FIG. 9c.
Complete Record.
Simple, direct-reading record. No subtraction, no counting, no
uncertainty. Any number of overlapping periods recorded on one
machine.]
The fingers continue in their circular motion backward, so that the
strands of the cord are wrapped around these fingers, as shown in Fig.
12.
[Illustration: FIG. 10.]
Continuing their circular motion, the fingers approach the strands of
the cord between the twisted portion and a part of the machine which
holds the ends of the cord, and the fingers spread apart as shown
in Fig. 13, so that they can pass over and grasp the strands thus
approached, as shown in Fig. 14.
The fingers then draw back through the loop which has been formed about
them, the fingers holding the grasped portion of the strands, as shown
in Fig. 15.
The knot is finished by the completion of the retracting movement of
the fingers through the loop, thus forming the bow of the knot as shown
in Fig. 16.
[Illustration: FIG. 11.]
The inventor found that one finger could have a purely rotary movement,
as if it were fixed on the arm and unable to move independently of the
arm, and the movement being as if the arm rotated like a shaft, but
the second finger must be further capable of moving toward and from
the first finger to perform the opening movement of Fig. 13, and the
closing movement of Fig. 14 by which it grasps the cord. The inventor
accordingly, from his exhaustive analysis of his problem, and his
invention or discovery of the proper finger motions, had further only
to devise the very simple mechanical device illustrated in Fig. 17 to
replace his fingers.
The index finger of the hand is represented by the finger _S_, which
is integral with the shaft _V_. The second finger of the hand is
represented by the finger _U_, which is pivoted to the first finger by
the pin _s_. The grasping movement of the finger _U_ is accomplished
by a spring _V'_ bearing on the shank _U'_, and its opening movement
is caused by the travel of an anti-friction roll _U"_, on the rear end
of the pivoted finger, over a cam _V"_, on the bearing of the shaft.
The shaft is rotated by the turning of a bevel pinion _W_ on the shaft
through the action of an intermittent gear. The necessity of drawing
the fingers backward to accomplish the movement between Figs. 14 and 16
was avoided by causing the tied bundle to have a motion away from the
fingers as it is expelled from the machine, the relative motion between
the fingers and the knot being the same as if the fingers drew back.
[Illustration: FIG. 12.]
Thus the accomplishment of a seemingly almost impossible function was
rendered mechanically simple by an evolution from the human hand, after
an exhaustive and ingenious analysis of the conditions involved.
It will be seen from the examples I have given that the constructive
part of inventing consists of evolution, and it is the association of
previously known elements in new relations (using the term elements
in its broadest sense). The results of such new association may,
themselves, be treated as elements of the next stage of development,
but in the last analysis nothing is invented or created absolutely out
of nothing.
[Illustration: FIG. 13.]
It must also be apparent, that pure reason and method, while not taking
the place of the inventive faculty, can clear the way for the exercise
of that faculty and very greatly reduce the demands upon it.
Where it is desired to make a broadly new invention on fundamentally
different lines from those before--having first studied the art to find
the results needed, the qualities of the material or other absolutely
controlling conditions should be exhaustively considered; but at the
time of making the inventive effort, the details should be dismissed
from the mind of how results already obtained in the art were gotten.
One should endeavor to conceive how he would accomplish the desired
result if he were attempting the problem before any one else had ever
solved it. In other words, he should endeavor to provide himself with
the idea elements on which the imagination will operate, but to dismiss
from his mind as much as possible the old ways in which these elements
have been associated, and thus leave his imagination free to associate
them in original and, as to be hoped, better relations than before.
He should invent all the means he can possibly invent to accomplish
the desired result, and should then, before experimenting, go to the
art to see whether or not these means have before been invented. He
would probably find that some of the elements, at least, have been
better worked out than he has worked them out. Of course, mechanical
dictionaries, and other sources of mechanical elements and movements
will be found useful in arriving at means for accomplishing certain of
the motions, if the invention be a machine. Many important inventions
have been made by persons whose occupation is wholly disconnected
with the art in which they are inventing, because their minds were
not prejudiced by what had already been done. While such an effort is
likely to possess more originality than that on the part of a person in
the art, there is, of course, less probability of its being thoroughly
practical. The mind well stored with the old ways of solving the
problem will, of course, be less likely to repeat any of the mistakes
of the earlier inventors, but it will also not be as apt to strike
out on distinctly original lines. It is so full, already, of the old
forms of association of the elements as to be less likely to think of
associating them in broadly new relations.
[Illustration: FIG. 14.]
[Illustration: FIG. 15.]
[Illustration: FIG. 16.]
Nothing should be considered impossible until it has been conclusively
worked out or tried by experiments which leave no room for doubt.
It is no sufficient reason for believing a thing won't work because
immemorial tradition, or those skilled in the art, say it will
not work. Many an important improvement has been condemned as
impracticable, by those in the art, before it has been tried.
A conception which an inventor has been striving for unsuccessfully
will sometimes come to him at a time of unaccustomed mental
stimulation. The slight stimulation of the movement of a train of cars,
and the sound of music, have been known to produce this effect. The
sub-conscious mind, after having been prepared by a full consideration
of the problem to be solved, will sometimes solve the problem without
conscious effort, on the part of the inventor.
[Illustration: FIG. 17.