Improvements in Metal Spokes for the Wheels of Velocipedes and other Vehicles.
Year: 1898

page_text: COMPLETE SPECIFICATION.
Improvements in Metal Spokes for the Wheels of Velocipedes and
other Vehicles.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by William George Allen and George Joseph
Capewell, both of Hartford, Connecticut, in the United States of America,
Engineers), and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
This invention relates to the construction of metal wheel-spokes for velocipedes
and other vehicles, and its object is to produce spokes which, while possessing great
tensile strength relatively to weight, and being readily and cheaply made, will
present a brilliant and elegant appearance in comparison with ordinary spokes.
The principal departure from ordinary practice in making the improved spokes
consists in forming the intermediate portion of irregular, or angular, instead of
circular, cross-section, leaving the ends rounded. There is further imparted to this
intermediate portion as a finishing step a twist, so that the edges, or angles, form
parallel helices. Spokes of this description impart to the wheel a highly
ornamental appearance, and, when in motion, the reflection of light from the
angles of the twisted spoke, produces a brilliant scintillating effect.
In making spokes according to this invention several difficulties have to be
overcome in order to obtain a successful result. If the blank were reduced to.
angular, or irregular, cross-section, and twisted from end to end it would have to
be drawn very hard in order to obtain the requisite tensile strength, and then the
bending of the headed end to form the shoulder would be difficult, and the metal
when bent be greatly strained and it would readily break at the bend. Moreover,
if the stock be angular, there would not be a suitable bearing under the head. It
also would be difficult to shape the other end and cut the thread thereon.
In making the improved spokes according to this invention the blanks are cut of
proper length from steel wire stock of circular cross-section, of the proper softness
and toughness to admit of threading and of bending the headed end without loss of
strength. The middle part of the blank is then brought to a triangular, square,
hexagonal, or other polygonal, or irregular, cross-section, leaving the ends circular
in cross-section. This change of shape is preferably effected by the use of rolls
having grooves of proper shape, and adapted to act on the middle part of the
blank, and finished if desired by swaging dies, but the means employed forms no
part of the invention, and may be of any suitable description. The physical effect
produced is to increase the hardness, compactness, and tensile strength, of the
middle portion, leaving the ends unaltered. The middle portion is then twisted
making a spiral of greater, or less, pitch as desired.
In changing the shape of the middle portion of the spoke it is advantageous at
the same time to reduce it in sectional area, and the procedure above described will
accomplish that result.
Obviously a blank having circular ends of greater diameter than the angular

page_text: reduced portion can be produced in other ways, but that hereinbefore described is
believed to be the most practical and effective.
The subsequent operations of heading, bending and threading are, or may be
performed in the usual way.
Many specific varieties of spokes can be produced within the scope of the
invention. As already stated the reduced middle portion may be of various forms
in cross-section, and the helices may have various pitches. The twist may also
extend over a part only of the reduced portion, and may be interrupted at one
place or at more than one place, thus presenting different effects to the eye, and
giving to different wheels distinctive appearances.
In the accompanying drawing Figures 1 to 5 inclusive illustrate blanks having
their middle portions of different polygonal form in cross-section, Figure 6 illustrates
a twisted spoke, broken in two, and Figure 7 illustrates another form of twisted
spoke, the end portions being broken away.
In Figures 1 to 5, a is the circular end, and b the polygonal intermediate portion
of the spoke. In Figure 1, this portion presents in cross-section a squaro, in
Figure 2, a triangle, in Figure 3, a pentagon, in Figure 4, an oblong parallelogram,
and in Figure 5, a hexagon.
In Figure 6, the middle portion of the finished spoke has twisted parts, or
sections, c alternating with plain, or untwisted, parts, d. A wheel provided with
these spokes will exhibit, while in motion, bright circular bands separated by dull
zones. Of course the number of twisted sections may be greater, or less, than that
shewn in this figure.
Figure 6 also shews one of the ends provided with a head e and shoulder f,
and the other with a screw-thread. It will be understood, however, that
the invention is applicable to spokes which are not shouldered at one end, or
which have attaching means other than those shewn.
Figure 7 illustrates a spoke which has the middle portion twisted from end to
end.
The foregoing description will make this invention clear to metal-workers, and
enable them to modify the construction of the spoke in various ways additional to
those illustrated.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. A metal spoke having end portions of circular cross-section, and an
intermediate portion of angular cross-section and twisted so that the edges form
parallel helices, substantially as hereinbefore described.
2. A metal spoke having end portions of relatively large diameter, and a reduced
middle portion of polygonal cross-section, twisted so that its angles form parallel
helices, substantially as herein before described.
3. A metal spoke having end portions of circular cross section, and a reduced
twisted middle portion of polygonal cross-section, substantially as hereinbefore
described.
4. A metal spoke having end portions of circular cross-section of relatively soft
metal and a harder middle portion of polygonal cross-section, the middle portion
being twisted, substantially as hereinbefore described.
5. A metal spoke having end portions of circular cross-section and a reduced
middle portion of polygonal cross-section, the edges forming parallel helices
extending over part of said middle portion, substantially as herein before described.
Dated this 8th day of February 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.