Improvements in the Construction of Flexible Shafts and Apparatus Used in the Manufacture of the same.
Year: 1887

page_text: Improvements in the Construction of Flexible Shafts and Apparatus
Used in the Manufacture of the same.
I, THOMAS GARE of 25 Booth Street Edgeley, Stockport in the County of
Cheshire, Boot and Shoe Manufacturer, do hereby declare the nature of this invention
to be as follows:-
―
My invention relates to improvements in the construction of flexible shafts, and in
particular to an invention for which Letters Patent were granted to Henry Walley
and myself, numbered 6588 and dated May 30th 1885, and to an apparatus for
manufacturing such flexible shafts.
This invention has principally for its object to facilitate the manufacture of much
larger and stronger flexible shafts, by modifying the construction described in
Patent No. 6588, and by employing a special apparatus for the manufacture of the
same.
In the said Patent No. 6588 the use of a layer of flat wire wound on the edge, or
the combination of a layer of wire of flat, and a layer of wire of round, section, has
been described.
In practice I have found that for flexible shafts of large diameter, say from one
inch upwards, a bar, (instead of wire) of flat section, wound or coiled on its edgo or
narrower side to form a hollow cylindrical body, will give a much stronger flexible
shaft than is the case when forming two layers of wire.
This kind of flexible shaft may also be used in lieu of bevel gearing to transmit
motion or power from one shaft to another & for driving screw propellers in steain
boats, in which case a core may be used, or the flexible shaft may be provided
externally, from distance to distance, with hoops so as to prevent the shaft from
curving.
The apparatus for winding wire or inetal bars of flat section consists of an
ordinary lathe-bed, which is provided with a slide rest, and head-stock, with hollow

page_text: On the slide rest I fix a guide or former provided centrally with a spindle, the
centre of which is in a line with the spindle of the head-stock.
The side of the guide or former pointing to the head-stock is formed with an
annular recess, which is concentric with the spindle of the head-stock and formed with
a slot which may be altered in size to suit circumstances, viz. size of bar to be used
for the flexible shaft.
When commencing to form a flexible shaft the guide or former is slid close to the
head-stock spindle, the spindle of the guide or former entering the hollow spindle of
the head-stock, the wire or bar to be formed into a flexible shaft is then passed
through the slot or opening in the guide or former and fixed to the head-stock
spindle.
The latter is then rotated and by the aid of the guide or former which moves
slowly away from the head-stock, the wire or bar gets wound onto the spindle of the
guide or former.
When a length of flexible shaft equal to the length of guide or former spindle has
been formed, the flexible shaft thus formed, is passed through the headstock spindle,
the guide or former brought up to the latter and the operation recommenced as
described.
Instead of winding the wire or bar onto a spindle moving with the guide or former,
the core or spindle may be fixed between two centres, and the guide or former having
a recess and slot as already described, and a hole concentric with the said rccess to
permit of its sliding on the core or spindle, onto which the wire or bar is wound, as
already described.
When forming flexible shafts of large sections. I preferably pass the bars through
a stationary furnace, or furnace moving with the slide rest and guile or former,
previous to being wound on the spindle, for the purpose of presenting the bar in a
red-hot state to the guide or former, and thereby facilitating the winding of same.
Dated 1st day of November 1887.

page_text: Improvements in the Construction of Flexible Shafts and Apparatus
Used in the Manufacture of the same.
I, THOMAS GARE of 25 Booth Street, Edgeley, Stockport, in the County of
Cheshire, Boot and Shoe Manufacturer, 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:-
My invention relates to improvements in the construction of flexible shafts, and in
particular to an invention, for which Letters Patent were granted to Henry Walley and
myself, numbered 6588, and dated May 30th 1885, and to an apparatus for
manufacturing such flexible shafts.
This invention has principally for its object to facilitate the manufacture of much
larger and stronger flexible shafts, by modifying the construction described in
Patent No. 6588, and by employing a special apparatus for the manufacture of the
same.
In the said Patent No. 6588, the use of a layer of flat wire wound on the edge, or
the combination of a layer of wire of flat, and a layer of wire of round, section, has
been described.
And in order that my invention may be more fully understood I have caused to be
appended hereunto two sheets of drawings marked with letters of reference, similar
leiters indicating like parts in the various figures.
Figs. 1&2 Sheet I. show various sections of metal bars used for the flexiblo
shaft.
Figs. 3&are partly longitudinal sections and partly side
improved flexible shaft shown respectively in a straight and curved
is an end view of the same.
elevations of my
state, and Figs. 5
Figs. 6 & 7, are side elevations, and Fig. 8 an end view, and show two modifications
of the same.
Figs. 9 & 10 Sheet II, are longitudinal sections of the apparatus for manufacturing
my improved flexible shaft.
Figs. 11 & 12 end views of various portions, and Fig. 13 a modification of the
same.
In practico I have found that for flexible shafts of large diameter, say from one
inch upwards, a bar (instead of wire) of flat section, wound or coiled on its edge or
narrower side, to form a hollow cylindrical body, will give a much stronger flexible
shaft than is the case when forming two layers of wire.
In carrying out my invention and referring to Sheet I, I take a metal red or bar a,
of suitable length, flat in section, see Figs. 1 & 2 and coil the same cylindrically on
its odge or narrower side, as closely and tightly as possible so as to leave a small coro,
and be free from any axial elasticity, see Figures 3, 4, & 5.
On coiling a rod or bar a of flat section on its edge or narrower side, and leaving a
core comparatively small to the diameter of the shaft, as described, the edges of the

page_text: coil internally, swell a little and join each other tightly, by reason of the acuteness of
the curve which the rod or bar is caused to describe, see Figs. 3 & 4, thus preventing
any axial elasticity, while externally the edges are a little apart, and provide space for
compensating for the different curvatures, without causing any axial elasticity, the
coil remaining always tight internally as represented by Fig. 4.
The proportions or sections of rod or bar a and size of core of the shaft, which in
practice I have found to answer best for most driving purposes, as regards the strength
and flexibility, are the following :-
110
understood that such proportions may be varied according to the
various requirement by respectively increasing or decreasing the flatness of the rod
or bar a.
By the use of a rod or bar a of flat section, and coiling the same on its edge or
narrower side in the manner described, I attain in the shaft great strength and
flexibility, at the same time freeing it from any axial elasticity, which is objectionable
as it interferes with the steady running of the shaft, and does not give strength
enough.
I may add that in order to get the coils externally rather closer together in shafts
requiring only a small amount of flexibility, it will be found of advantage to slightly
taper the section of the bar, as shown in Fig. 2.
The degree of flatness of the rod or bar a renders the shaft also more or less
flexible and strong, the greater the degree of flatness is, the greater will be the degree
of resistance, and vice versa, while the pitch of the coil will decrease, and allow the
necessary curvature without being subject to axial elasticity.
This kind of flexible shaft may also be used in lieu of bevel gearing or as a flexible
coupling to transmit motion or power from one shaft to another, and for driving
screw propellers in steam boats in which case a solid core a¹ may be used, as shown in
Fig. 6, or the flexible shaft may be provided externally, from distance to distance,
with hoops a² see Fig. 7, so as to prevent the shaft from curving.
Referring to Figs. 9. 10. 11. & 12, Sheet 11, the apparatus for winding wire or
metal bars of flat section consists of an ordinary lathe bed b, which is provided with a
slide rest c, and head stock d, with hollow spindle e.
On the slide rest c I suitably fix a guide or former f provided with a spindle g
passing through the hole y' formed therein, the centre of which is in a line with the
spindle e of the headstock d.
The side of the guide or former f pointing to the headstock d is formed with an
annular recess h, which is concentric with the spindle e of the headstock d, and formed
with a slot , which may be altered in size to suit circumstances, viz., size of bar, to
be used for the flexible shaft and over which is fixed a small plate ² to prevent the
bar a from running out, see Figs. 10 & 11.
When commencing to form a flexible shaft, the guide or former is slid close to the
head-stock spindle e, the guide or former spindle y entering the hollow spindle e of
the headstock d, and being secured thereto by means of the chuck fixed thereon, or
other suitable means.
One end of the wire or bar a io be formed into a flexible shaft is then passed through
the slot or opening in the guide or former and fixed to the headstock spindle e
or chuck i, preferably as more clearly shown in Fig. 12.
The latter is then rotated and by the aid of the guide or former which moves
slowly away from the headstock d the wire or bar geis wound onto the guide or
former spindle g.
When a length of flexible shaft about equal to the length of guide or former
spindle has been formed, the flexible shaft thus formed is passed through the head-
stock spindle e, the guide or former brought up to the latter, see Fig. 10, the guide
9

page_text: or former spindle e drawn out into its former position and the operation re-commenced
as described.
In lieu of fixing the guide or former spindle g to the headstock spindle e or its
chuck the same may be made much shorter, and fixed into the guide or former f, see
Fig. 13 so as to move with it, and draw itself continuously out of the shaft formed,
or the guide or former spindle g may be fixed between two centres; on the bed the
guide or former in each case having a recess and slot has already described, and
a hole concentric with the sai recess to permit of it sliding on the core or spindle g,
onto which the wire or bar a is wound, as already described.
If deemed necessary a spring or a weight see Fig. 9, may be employed to press
the guide or former y always against the coils of the shaft, thus coiling the bar as
tightly as possible.
When forming flexible shafts of large sections, I preferably pass the bars through a
stationary furnace, or furnace moving with the slide rest and guide or former,
previous to being wound on the spindle, for the purpose of presenting the bar in a
red hot state to the guide or former f, and thereby facilitating the winding of same.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim, is:-
:-
1st. A flexible shaft, consisting of a metal bar of flat section coiled on its edge or
narrower side, the coils of which internally are close on, and externally a little apart
from each other, substantially as and for the purpose specified.
2nd. The apparatus for the manufacture of flexible shafts by coiling a metal bar of
flat section into a cylindrical body, consisting of a slide e provided with a guide or
former, formed with a cylindrical recess h, slot h', and guide or former spindl
hole g in conjunction with a headstock d, the hollow spindle of which serves to hold
one end of the bar or flexible shaft a and guide or former spindle y substantially as
set forth.