Improvements in "Gears" or Driving Chains and Wheels, specially applicable for Cycles.
Year: 1896

page_text: Date of Application, 6th July, 1896-Accepted, 12th Sept., 1896
COMPLETE SPECIFICATION.
Improvements in "Gears" or Driving Chains and Wheels, specially
applicable for Cycles.
We THOMAS GRACE of Ivy Street Darlington near Sydney in the Colony of
New South Wales Builder, and LOUIS CARNEGY AULDJO of Equitable Building
George Street Sydney aforesaid Consulting Engineer 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:-
This invention relates to driving wheels and chains or "gears" which have been
specially devised in order to obtain effective results with ease of propulsion in the
working of geared cycles though these improvements are equally. as well serviceable
with like gear in the transmission of power for other purposes. These results are.
attained by minimising the frictional contact of the driving chains with the
chain wheels and by preventing the accumulation of dust and dirt within the
wheels.
These improvements in, gears or driving chains and wheels specially applicable
for cycles consists in the peculiar construction of driving chain carrying friction
rollers outwardly of its links; in the peculiar construction of wheel or pinion having
teeth like circular ratchet teeth; in the peculiar construction of wheel or pinion
having two sets of teeth forming the sides of a trough as much as possible
bottomless; in the peculiar construction of wheel or pinion having circular
trucks or supports (preferably loose) outwardly of the toothed rim. and in the
particular combinations and arrangements of parts hereinafter set forth.
According to these improvements wheels and pinions have a working face or
faces consisting of a circular periphery, carrying teeth rising or protruding from
it. Each tooth has a working edge or face (when the wheel is a driver its
advancing or leading edge or face) straight and rising at an obtuse angle to a
tangent of the circular periphery and has its following or trailing edge or back
formed of curved lines appropriately providing strength for it and oppositely when
the wheel is a driven one its working or following or trailing edge or back is the
In other
straight one and the advancing or leading edge or face is the curved one.
words each tooth or spur of chain wheels constructed according to this invention
might be described as a circular ratchet tooth of which the straight face of the
driver is the working or leading or advancing face and the straight; face of the
driven is the working or following or trailing back. Between the working faces or
edges of the teeth and the idle edges or back of said teeth is the circular part.of
the periphery of the wheel.
According to another of these improvements the wheels and pinions have a
hollow or rather a trough shaped rim from which has been removed as much as
possible of the bottom of the tr ugh leaving only just so much, as is necessary to
hold the sides together and it is these circular sides or peripheries which form
rests or tracks or supports for rollers on the driving chain hereinafter described
and upon these are formed the teeth for gearing with said rollers of said chain.
Instead however of the roller eing geared with teeth on these trough sides.or
circular peripheries the chain may be driven by teeth upon a central disc or rim
and then according to these improvements the central toothed disc or wheel rim
bas u on either side of it a die rim preferably loose upon the axle or upon the
boss of the wheel rim and wit. wthout friction rollers or ball bearings said discs
or rims forming tracks or supp or the rollers of the driving chain.

page_text: According to these improvements a peculiarly constructed driving chain is used
in combination with the wheels and pinions hereinbefore described or in combination.
with other trough shaped chain wheels or other wheels having side discs or chain
roller tracks. This driving chain has central or inside links and sets of outside
links the two parts constituting the sets or outside links being jointed to the ends
of the inner links. In one modification of this chain the central or inner links are
made as thin as possible consistent with strength and are set vertically being
widened to give them strength and having their edges chamfered so as to adapt
them to pass easily through the air. The lower edges of said inner links are
preferably straight and their upper edges "roached " or curved. The total
breadth or width of the links of this chain adapt them to travel easily within the
trough sides or teeth rims of the wheels and pinions hereinbefore describe.l. In all
forms of this chain certain joint pins are extended on either side and carry frictional
rollers equal or slightly exceeding in width the thickness of each side of the trough
or teeth rim of the wheels or of the side discs or chain roller tracks of the wheels
and these rollers on either side travel on said rims or on said discs and used with
the trough shaped wheel they take against the working edges of the teeth thereon.
It is an essential part of these improvements that these frictional rollers should not
be placed on the ends of every joint pin but there should be left between each set
of said frictional rollers one or more joints in the chain whose pins do not carry
rollers so that increased flexibility and "play" is given to the chain between the
points at which its weight is supported.
This improved chain with the frictional rollers on some of the joint pins may be
used on any wheel with the central toothed disc or wheel rim in which case the
internal links would gear with the teeth thereon. It is however preferably used
with a wheel having a central toothed rim and side dises or roller tracks in which
case the rollers travel on and are supported by said side discs and the internal
links freely gear with the central toothed rim which may if desired have teeth
constructed as hereinbefore described with working and idle faces or edges.
But in order that this invention may be clearly understood reference will now be
made to the drawings herewith in which
Figure 1 is a side elevation of a driving chain constructed according to this
invention passing over chain wheels also constructed according to this invention
and suitable for use upon the pedal spindle and the driving axle of a bicycle although
such chain and wheel and pinion might be used for other purposes.
Figure 2 is a plan of such chain and chain wheels while Figure 3 is a cross section
of the chain wheel and Figures 4 and 5 are cross sections of modified constructions
of the same.
Figure 6 is an elevation of a chain wheel or pinion having a central toothed rim
(with teeth of ordinary construction though they might have a configuration similar
to those illustrated in Figure 1) and Figure 7 is a section of same.
Figure 8 is an elevation and Figure 9 is a plan partly in section of a driving
chain having friction rullers on alternate link pins and adapted to travel on a
wheel such as that shown in Figures 6 and 7 or on any ordinary toothed wheel
but preferably on one having side dises or chain roller tracks whether they be loose
or fast.
A is the driving wheel and B the driven pinion around which travels the chain
consisting of side links C and central links D and on extended joint pins of some
of said links are the friction rollers E. The wheel A has rims A' on either side
and a base or bottom A joining said rims where necessary say at the arms so that
open spaces A will be left through which dust and dirt will fall clear of the wheel
and so that an accumulation of dust and dirt between the rims A' will be prevented.
Each tooth on the rims of the driver is formed with a leading face a forming an
obtuse angle with a tangent to the rim A' andl a trailing edge a of curved or other
convenient outline joining into part a' of what would be but for the protruding
teeth the circular periphery of the rim. The teeth of the driven pinion B are
formed in exactly the same way but in this case the straight face b'becomes the

page_text: trailing but working edge of the tooth the curved face is the advancing but idle
edge and the circular part & completes the periphery of the rim. The links C
and D are jointed together by pins c and d and the joint pias e are extended
outwardly to take upon their outer ends the rollers E free to revolve theres and
it is essential that there be one or more of the short joint pins e between the longer
joint pins d which carry these rollers E. The central link D is made vertically as
wide and laterally as narrow as possible and to obtain this width the inside edge is
made practically flat while the outside is made "roached" or curved as shown and
if it be necessary these links are made relatively wider than shown in the drawing.
In order that these links may pass as freely as possible through the air and maintain
their equilibrium in their vertical position the roached or curved backs and the inner
edges are chamfered,
The modified constructions of wheel as shown in Figures 4 and 5 are easily
understood for in Figure 4 the sides of the trough or rims are forged or cast solid
with the arms or a disc and parts of the bottom of the trough or rims are cut
away to make open spaces like those marked A3 in Figures 1, 2, and 3. In
Figure 5 the trough of the wheel is constructed by bolting an additional rim on to
a disc or to arms and similar spaces or openings are left in the bottom of the
trough.
In operation motion is given to the driving wheel as well understood, the chain
being supported by the friction rollers E running on the parts a' and 6 of the
circular peripheries of the wheel and pinion. The motion of the driver wheel
causes the facings a' of the teeth to press against the rollers E and drive or push or
drag the chain around and the peculiar shape of these teeth enable the load on the
chain to be somewhat easily distributed over the teeth in action and the joints of
the pin between the roller impart a very large amount of flexibility and "play
the chain and assist materially in the fair distribution of the load upon the chain
in action. The shape of the teeth also enables the easy separation of the roller E
from the teeth the moment that they are not required to do any further work.
The action of the chain upon the driven pinion B is just similar the weight of the
chain being supported by the rollers E on the part the rollers E acting against
the faces b of the teeth in action and the chain having flexibility by reason of its
joints between the sets of rollers the work is evenly distributed between the
rollers E and the rollers easily disengage from the pinion when they have no longer
power to impart motion to the tooth going out of action.
In the modification illustrated in Figures 6 and 7 the wheel H has a central
toothed rim H' the teeth H2 whereon are of ordinary construction (though they
might be peculiarly constructed as hereinbefore described with reference to
Figure 1). The discs I having circular peripheries from side tracks or supports
for friction rollers on the driving chain and these discs I are upon either side of
the rim H' and they may be integral with said rim but preferably as shown they
are loose to revolve upon the boss H³ of the wheel. In the bearings on the
boss H that is between said boss and the boss I¹ of the discs friction balls or
rollers may be inserted the whole being kept together by collars or flanges on the
spindle carrying the wheel. The driving chain is made with links C and D and
with rollers E on some of the joint pius as herein before described and the ends of
the internal links D gear with the teeth H2 of the wheel H while said rollers E
support the weight of the chain with "play" or flexibility between the points of
support preferably the joints of the chain and rollers are made as shown though any
approved construction would also do.
It is to be understood that though but one joint of the chain occurs between the
sets of rollers in the chain described and illustrated yet according to the pitch of
the wheel there may be two or more joints between each set of rollers and though
the most serviceable construction of the teeth has been explained and shown
yet other formations of teeth might be used so long as a circular periphery is
provided between said teeth upon which rollers may take to support the weight of
the chain. It is to be further understood that we do not confine ourselves to any

page_text: particular kind of wheel and pinion and chain so long as the essential parts of this
invention -as hereinafter claimed may be applied.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed.we declare that what
we claim, is
First. In "gears" or driving chains and wheels for the purposes set forth a chain
consisting of double and single links the internal or single links of which are widened
vertically set vertically and have their edges chamfered to the centre substantially
as herein described and explained.
Second. In "gears" or driving chains and wheels for the purposes set forth a
chain on some of the joint pins of which and outwardly on either side are friction
rollers there being one or more joints of the chain between each set of rollers
substantially as herein described and explained.
Third. In "gears" or driving chains and wheels for the purposes set forth a chain
wheel or pinion having the teeth somewhat far apart and having between each tooth
a part of the circular periphery from off which said teeth protrude substantially as
herein described and explained.
Fourth. In "gears" or driving chains and wheels for the purposes set forth a
chain wheel or pinion having two sets of teeth forming the sides of a trough which
is constructed as far as possible bottomless substantially as herein described and
explained.
Fifth. In "gears" or driving chains and wheels for the purposes set forth a chain
wheel or pinion having a central toothed rim and side discs or circular peripheries in
fast or loose connection with said toothed rim substantially as herein described and
explained.
Sixth. The particular constructions of driving chain and the particular con-
structions of chain wheels and pinions substantially as herein described and explained
and as illustrated in the drawings.
Dated this Twenty-second day of May One thousand eight hundred and
ninety-six
THOMAS GRACE.
LOUIS CARNEGY AULDJO.