Year: 1886

page_text: I, PROSPER ACHILLE DOHIS, of 10 Rue Elisa-Borey, Paris, (France) Engineer-
Contractor do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement:―
The object of my invention is to substitute helical springs for the ordinary
spiral barrel springs, whereby the numerous disadvantages of the latter are
avoided.
Hitherto flat springs of greater or less thickness, width and length have only
been used wound in barrels of suitable dimensions. This form is suitable for
borological purposes, but is not practical in using strong springs, required to exert
a great power, as the springs require barrels of large dimensions which are
consequently costly, heavy and cumbersome, and no matter how strong, they are
liable to break from the sudden distension or unwinding of the spring, and present
a source of danger.
Another great disadvantage in the use of such springs is the loss of power,
which results from the frictional contact of the coils of the spring upon each other,
in order to overcome which a certain amount of power is lost instead of being
utilized for actual work.
It may even happen that this frictional contact may be sufficient to stop the
unwinding of the spring for a moment, and the spring suddenly unwinding
might break or burst the barrel, causing the disadvantages already mentioned.
The friction between the barrel and the edges of the spring also presents
disadvantages of the same nature. Finally, it often happens that the spring
breaks at its point of attachment to the shaft or to the barrel, such attachment
being made by removing part of the material of which the spring is made, thus
weakening the spring at such points.
In order to overcome these disadvantages I propose using helical springs, not as
they have hitherto been used, that is to say by using only their longitudinal
extension, but by causing them to work as spiral springs from the centre to the
circumference, or rather outwards from the axis of the cylindrical surface upon
which the spring is wound, whilst at the same time its longitudinal extension is
also utilized.
The shaft A is made much longer than for a spring of ordinary form, and to one
extremity one end C of the helical or cylindrical spiral spring is secured, the
extension at C allowing a notch to be formed to receive the screws c without
reducing the working length of the spring B. The other end D of the spring is
fixed to a sleeve E which can turn loosely on the shaft A; this sleeve E is con-
nected by gearing HF with the mechanism to be operated, which naturally
opposes a sufficient resistance to the winding when the helical spring constituting
this invention is being re-wound. The re-winding is effected in the usual manner,

page_text: by means of a key or handle M, which actuates the shaft A. K is a ratchet wheel
and R a pawl to retain the spring in its wound up position. It will readily be seen
that the spring will be put in tension by approaching the core or shaft A in spirals,
which will become more and more tightened until they come in actual contact
with the shaft, when the spring will be completely wound up, and can then unwind
by its end D and operate the gearing H F. The shaft A is not smooth, is surface
being scored or preferably provided with slightly projecting ribs in the form of a
continuous spiral, so as to prevent the spring coming in close contact with the core
or shaft A, which would result in the same disadvantage as above indicated in
connection with the contact of the different spirals of ordinary springs. The
projections should not be close together, but rather wide apart, as it is advisable not
to unnecessarily increase these points of contact, which simply serve to prevent
the binding of the spring on the shaft A. At the same time the construction must
be such that when the spring is fully wound the edges of the adjacent spirals do
not touch.
The spring thus formed offers a further advantage, inasmuch as that all the
spirals are of equal curvature, are subject to the same strains and operate with the
same force, whereas, in ordinary springs, the spirals which are wound directly on
the axis are subject to the greatest strain, thus increasing the chances of breakage.
Again, the re-winding is much easier than in ordinary springs and more rapid ;
moreover, it is easy to maintain the tension of the spring by giving a few turns to
the handle M, without interfering with the movement of the gearing H F.
The apparatus actuated can therefore operate without any interruption for
re-winding the spring, which has not hitherto been possible.
Several springs may be used at the same time to work the same apparatus, such
springs being caused to work alternately, or all at the same time, and it will be
seen that anyone can himself replace one spring by a stronger or weaker one,
which cannot be done in ordinary cases where it is necessary to change the
barrel and the spring contained in it, that is to say, the whole of the actuating
mechanism.
It will be readily understood that the reason that the spring is more rapidly
re-wound, is because the winding acts simultaneously on all the spirals of the spring,
instead of acting successively as in ordinary springs.
Finally, it will also be apparent that by my new arrangement the chance of
breaking the spring is avoided as well as the breaking of the barrel, as the
latter is abolished, and the other disadvantages above referred to will also be
obviated.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The improved construction of spring of a helical or cylindrical spiral form
operating from the centre to the circumference by means of a suitable arrangement,
substantially as herein described and shown in the drawings.
2. The method of securing the helical springs, substantially as herein described
and shown in the drawings.
3. The employment of one or more of my improved form of spring for actuating
all kinds of machinery, substantially as described.
Doted this 6th dow of Combo 1000