Year: 1896

page_text: I, Dr. EUGENE LOUIS DOYEN of 5 Rue Cotta Reims (Marne) in the Republic of
France do hereby declare the nature of this Invention to be as follows:-
My Invention relates to improvements in flexible transmission shafts in which
short tubular adjacent parts are threaded on a core and can be displaced angularly to
each other by turning on spherical surfaces. The said tubular parts are made alike
so that they can be readily interchanged and are provided at their ends with teeth or
tennons and grooves or mortices whereby they are kept in engagement when
rotated.
A flexible shaft according to this Invention is formed of a series of tubular parts,
which may vary in length, threaded on a flexible cable formed by a spirally wound
steel band or by a metal cable or where only a small amount of energy is to be
transmitted, a silk cord or string may be used which is rendered non-extensible by
any suitable means for example by a central steel wire. This core forms a flexible
tube and support on which the aforesaid tubular parts are threaded and fixed either
at the two ends of the cable only or also at other parts thereof, and it is not used
for the transmission of motion. To prevent the said tubular parts cutting the central
core wlien moved angularly to each other the tongues and grooves at the ends of the
parts are chamfered or made with angles corresponding to the maximum angle of
inclination to which the parts may be twined.
Such chamfering of the groove and tongue joints is however unnecessary in the
case of shafts of very small diameters.
The mortices and the tennons are cut in the body of the tube so as to form a
spherical connection between two adjacent parts the centre of the sphere on which
the parts turn being on the axis of the tube: in other words the mortices on the end
of one element form concave spherical parts exactly corresponding to the tennons
which form convex spherical parts on the end of the adjacent element, the centre of
the sphere common to the two surfaces being on the axis common to both.
Dated this 31st day of August 1896.

page_text: Improvements in Flexible Transmission Shafts.
I DR. EUGENE LOUIS DOYEN of 5 Rue Cotta Reims (Marne) in the Republic of France
do hereby declare the nature of my Invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
My Invention relates to improvements in flexible transmission shafts in which
short tubular adjacent parts are threaded on a core and can be displaced angularly to
each other by turning on spherical surfaces. The said tubular parts are made all
alike so that they can be readily interchanged and they are provided at their ends
with teeth or tenons and grooves or mortices whereby they are kept in engagement
when rotated.
I will describe my Invention with reference to the accompanying drawings.
Figure 1 is a side elevation of a flexible shaft constructed in accordance with my
Invention.
Figure 2 is a transverse section of the same taken on the line A B Figure 1
and
Figure 3 shews in longitudinal section tubular elements of the shaft with their
spherical surfaces on which they turn, and the central flexible core.
The flexible shaft is formed of a series of tubular parts b which may vary in length,
threaded on a flexible cable a formed by a spirally wound steel band or by a metal
cable or where only a small amount of energy is to be transmitted, a silk cord.or
string may be used which is rendered non-extensible by any suitable means Buch for
example as a central steel wire. This coro forms a flexible support on which the
aforesaid tubular parts b are threaded and fixed either at the two ends.of the cable
only or also at other parts thereof, and it is not used for the transmission of motion.
The said tubular parts b are shewn formed at their ends with tongues or tenons c and
mortices or recesses d, these parts being made alike in all the elements so that the
tenons of one element correspond and can fit into the mortices of an adjacent element
when threaded on the flexible core a as aforesaid. To prevent the said tubular parts
outting the central core at their joints when moved angularly to each other the
tongues or tenons c and grooves or mortices d are ohamfered or made with angles (as
shewn in the drawings) corresponding to the maximum angle of inclination to which
the parts may be turned.
Such chamfering of the groove and tongue joints is however unnecessary in the
case of shafts of very small diameters. The mortices d and the tenons c are so cut
in the body or material of the tube as to constitute a spherical connection between
two adjacent parts or elements thereof the centre of the sphere on which the parts
turn being on the axis of the tube; in other words the mortices & on the end of one
element form concave spherical surfaces exactly corresponding to the tenons c which
form convex spherical surfaces on the end of the adjacent element, the centre of the
sphere common to the two surfaces being on the axis common to both.
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. In the construction of flexible shafts formed of tubular elements with spherical
connections the combination of the said elements with a flexible cable cord, or
analogous support on which the elements are threaded substantially as hereinbefore
described with reference to the accompanying drawings.

page_text: 2. In flexible shafts of the kind claimed in the preceding claiming clause forming
the connecting tubular elements with tenons and mortices having surfaces chamfered
or made with angles so as to admit of the transmission of motion at any desired angle
without injury to the flexible core substantially as described.
Dated this 5th day of May 1897.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.