Improvements connected with the Driving Mechanism of Bicycles, Tricycles, and the like.
Year: 1893

page_text: Date of Application, 21st Aug., 1893
Complete Specification Left, 1st May, 1894-Accepted, 16th June, 1894
Improvements connected with the Driving Mechanism of Bicycles,
Tricycles, and the like.
I, BERNARD CHARLES HUGUES CADOT of 27 Rue Caumartin Paris in the
Republic of France, Retired Civil Engineer, do hereby declare the nature of this
invention to be as follows:-
My invention has for its object various improvements which I have introduced
in velocipedes and other like vehicles.
These improvements, which enable the speed of velocipedes, or the like, to be
rapidly varied, consist in the use of a toothed cone or stepped wheel having several
speeds in one or more parts, and of an endless link chain capable of being
instantaneously opened by the employment of suitable links, hereinafter described,
which insure great rapidity in opening and closing together with an absolute
necurity.
In velocipedes, the power applied to the axle of the pedals is generally transmitted
to the axle of the driving wheels by means of two cog wheels of different radius
with which an endless round link chain engages. The toothed pinion fixed on the
transmitting axle has the greatest radius. Under these conditions, the number of
revolutions of the driving wheel, whilst greater than that of the axle, is, nevertheless,
in constant proportion to the latter. The speed can only be varied by varying, in
the same proportion, the number of revolutions of the transmitting axle. The
force or efforts applied to the pedals must, therefore, vary in intensity and
multiplicity.
Each of the single cog wheels is replaced exactly in its position by a group of
cog wheels, the number of which corresponds to the alterations of speeds which it
is desired to obtain, the different diameters of these wheels being calculated in such
a way that the sum of the number of the teeth of the corresponding wheels remains
constant, and, consequently, the same chain will indifferently actuate any pair of
corresponding wheels. In practice, four or even three changes of speed will suffice
for tricycles, arising from three or four wheels of different diameters per axle. For
bicycles, three will be amply sufficient. In order to show the great difference of
speed which may be obtained, there may be imagined an extreme combination of
three different wheels only, of which the following is a brief description
The three cog wheels, suitably arranged side by side, are connected in such a
way as to form, to a certain extent, two cones with three crowns each.
The diameters of these wheels may vary according to requirements, keeping
them, however, as regards their proportions, practically within the limits adopted
for the single wheels at present employed; but the diameter of the centre wheels
must be very little greater (about 4) to the average of that of the two others.
The number of teeth of two of the wheels must be exactly half the total of the
teeth of the remaining four wheels, which, for this reason, must always have an
even number. Thus, if the number of teeth of the large wheel is 22 and that of
the small wheel 8, that of the centre wheel will be 15.
The centre wheel is placed between the other two. Its hub, spokes and rim are
in the same perpendicular plane to the axle. The smallest wheel which is solid
has a flat face where it is in contact with the centre wheel and it is in a vertical
plane; but its opposite face is concave, so that its felly has a much greater
thickness than its hub and leaves between the teeth and the face of the centre wheel
sufficient space to allow of the passage of the endless chain which engages with
these teeth.

page_text: The large wheel has its hub of the same thickness as that of the centre wheel,
and fits exactly against this latter, but its spokes are curved and bent inwards in
such a way as to be first rivetted to the felly of the centre wheel, and then to
extend to the crown, which they support beyond the vertical plane of the central
wheel in order to allow of the passage and play of the endless chain.
hubs united are not thicker than the hubs of ordinary single wheels, and the set of
The three
three wheels bolted together is fixed on the axles in the same place and under the
same conditions as the single wheels at present employed.
The two groups of cog wheels are keyed on their respective axles symmetrically
vis-à-vis one another, in a vertical plane passing through the axis of the machine
for tricycles, and in a vertical rod, the plane of which is parallel with this axis, for
bicycles.
In this position (with the increase of 15 of the diameter of the centre wheels) the
length of the endless chain which connects any one of the three groups of spur
wheels remains constant, and the same chain may be fitted to each of these groups
on condition that it can be released from the group with which it is engaged in
order to be passed over another, which necessitates its being able to be easily and
surely opened and re-closed.
The following arrangements are included in this invention in order to obtain
rapidity and safety in the opening and closing of the chains:-
An endless chain or band with full links.
One of the full links is formed by the union of two half links, each having a
trunnion and an axis, and one of them terminated by a dovetail tenon of equal
breadth to the link and having a considerable thickness at its thinnest part.
The other, by a symmetrical jaw or mortise in which the dovetail tenon can fit
exactly sliding along a plane parallel to that of the base of the half links. In
order to allow of the tenon and mortise having sufficient length whilst giving the
united half links the exact length of the other full links of the chain, or to increase
the distance apart of the axes whilst diminishing the thickness of the external part
of the link which forms the eye in which, besides, they are fixed, the extreme
circular part of the eye of the cheeks, in which these axes are engaged, is flattened
vertically. In order to facilitate the entrance of the tenon in the mortise by being
slid horizontally, the slopes of its side face, which must come in front of the side
opening of the mortise, are cut off to a blunted edge. The slopes of the mortise
on the lateral face opposite the entrance are, on the contrary, hollowed out inwards
in such a way as to prevent the tenon from exceeding, in its horizontal movement,
the position which it is intended to occupy, in which, when once placed, it is held
by a screw passing through the upper spur of the jaw or mortise and penetrating
into a recess formed at a suitable point of the upper face of the tenon.
This screw passes through a little india rubber washer, on which it presses and
which, by its relative adherence, prevents its becoming unscrewed spontaneously.
The endless roller chain is formed of a series of rollers engaging in the recesses
of the toothed wheels and connected by cheeks (or side pieces) the eyes of which
enter the axes of the rollers.
at will, one of the cheeks of the movable links is formed of a spring which in its
In order to allow of this chain being cut and re-closed
natural position tends to close on approaching the opposite cheek.
being fixed on the roller engaged in the end of the axis of the trunnion tends to be
This spring
compressed against the cheek of the following link; an effort proportionate to its
tension, exerted from the inside outwards, is necessary to cause it to move from this
normal position.
In
The side forming the second cheek of the movable link is like all the others; but
the end of the axis of the roller which engages in the eye of this side is slightly
curved so as to form a hook and thus to prevent this side cheek slipping out.
order that the hook axis may always preserve the same position to the side cheek
which it connects, it is fixed to the cheek by a fixed link.
Under these conditions in order to open the movable link, the cheek spring is
drawn from the inside outwards by introducing between the two cheeks a suitable

page_text: piece of wood or iron forming an angle so as to cause this side spring to come out
of the eye of the axis in which it was engaged; then by a rotary motion on its
other axis it may be lowered so as to completely release the roller from the fixed
link which it connected to the movable link. The end of the curved axis of this
roller is then easily disengaged from the eye of the side-cheek of the movable link
and the chain is open.
In order to re-fasten it, the end of the curved axis is first engaged in the eye of
the side-cheek of the movable link, then opening the spring cheek of the movable
link, its eye is brought in front of the axis of the fixed roller, which engages
therein of itself as soon as the spring cheek is released.
This method of fastening presents a very great security, increasing with the
force of the pressure of the spring. In fact, if this pressure is great enough, the
hook of the axis of the roller of the fixed link may be dispensed with, the force
exerted by the strain of the chain on the cheeks tending to approach them rather
than to separate them, and, consequently, being added to the effect of the spring in
order to ensure the cheeks of the movable link being maintained in their normal
position.
The system of movable cheek spring is applicable without the slightest
modification to chains with solid links. In this case, instead of the solid link, it
would be the link with cheeks connecting two full links that would open.
In all these systems, after having opened or severed the chain, it is removed
from the set of wheels on which it was engaged in order to be shifted on to the set
which it is desired to operate, and it is then re-closed. This very simple operation
scarcely requires a minute.
Dated thin 10th 1
f. 1902
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements connected with the Driving Mechanism of Bicycles,
Tricycles, and the like.
1, BERNARD CHARLES HUGUES CADOT of 27 Rue Caumartin, Paris in the
Republic of France, Retired Civil 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 :-
My invention has for its object various improvements which I have introduced
in bicycles, tricycles, and other like vehicles.
These improvements, which enable the speed of velocipedes, or the like, to be
rapidly varied, consist essentially in the use of a toothed cone or stepped wheel
having several speeds, in one or more parts, and of an endless link chain capable of
being instantaneously opened by the employment of suitable links, hereinafter
described, which insure great rapidity in opening and closing together with an
absolute security.
In order to allow of the invention being better understood, reference will now be
made to the accompanying drawing, on which
Figure 1 is an elevation of the two toothed cones of a velocipede showing the
different positions of the endless chain which operates them.
Figure 2 is a section of the whole arrangement in a plane following the axes of
rotation.
Figure 3 is a section of a dovetail fastening link of the link chain.
Figure 4 is another fastening link of a chain with roller links.
In velocipedes, the power applied to the axle A of the pedals is generally trans-
mitted to the axle A¹ of the driving wheels by means of two cog wheels of different

page_text: "
radius with which an endless "Galle link chain engages. The toothed pinion
fixed on the transmitting axle A has the greatest radius. Under these conditions,
the number of revolutions of the driving wheel, whilst greater than that of the
axle A, is, nevertheless, in constant proportion to the latter. The speed can
only be varied by varying, in the same proportion, the number of revolutions of
the transmitting axle A. The force or efforts applied to the pedals must,
therefore, vary in intensity and multiplicity.
In this improved arrangement, each of the single cog wheels is replaced exactly
in its position by a group of cog wheels, the number of which corresponds to the
alterations of speed which it is desired to obtain, the different diameters of these
wheels being calculated in such a way that the sum of the number of the teeth of
the corresponding wheels remains constant, and, consequently, the same chain
will indifferently actuate any pair of corresponding wheels. In practice, three
changes of speed will suffice, arising from three or four wheels of different
diameters per axle, but any desirable combinations may be realised on condition
of maintaining constant the number of teeth of each group.
The arrangement shown on the drawing yields the following proportions of the
number of teeth of the pedal axle pinions, and of the corresponding ones of the
driving axle for three changes of speed :-
24:
34 18 that is to say, 3: 1-66: 1.
The three cog wheels of each group respectively B C D & b c d suitably
arranged side by side, are connected in such a way as to form, to a certain extent,
a single wheel with 3 crowns.
In order to reduce the weight of the arrangement, the two wheels B D bd
may be bolted to the centre wheel C or c respectively, which allows of a large
part of the spokes being dispensed with, and this is the combination shown on the
drawing.
In order that the endless chain, carried successively over each of the corre-
sponding couples having all the same total number of teeth, may maintain the
same tension, it is necessary to give the diameters of the crown of these wheels
(starting from their circumferences) a total length slightly exceeding the average.
The endless chain connecting the two wheels of most varying diameter is in fact
longer than that which connects the two wheels, the diameter of each of which is
half of the sum of the diameters of the two first D d. The variation depends
both from the difference in the diameter of the wheels and in the distance of the
axles on which they are keyed, but its variations are so trifling that, in all ordinary
cases, there may be adopted as correction the one which applies to the combination
shown on the drawing, always allowing the usual distance of 55 to 60 centimetres
for the interval or space between the axles A A¹. In this case, the diameter of
the smallest wheel D must be increased by 40, say by 18 = .004 metres.
That of
the central wheel C must only be increased by 002 metres.
In order to further diminish the importance of these corrections, it is better to
take as a standard the pair of central wheels C c. The diameter of the small
wheels D d will then only require to be increased by 2 millimetres. The diameter
of the large outer wheel B must, on the other hand, be 2 millimetres less than would
be implied from the proportionate average of the sum of the diameters of each
group. As the number of teeth remains the same, those of the large wheel B must
be a little approached and those of the small wheel D a little more separated than
that of the centre wheel C. This latter taken as a standard will give for each
interval between the teeth a reduction of 13 of a millimetre for the large wheel B
and an increase of of a millimetre for the small wheel D.
The two groups of cog wheels are keyed on their respective axles, so that they
symmetrically vis-à-vis one another, in a vertical plane passing through the axis of
the machine for tricycles, and in a vertical plane parallel with this axis, for
bicycles.
In this position, the same chain may be fitted to each of these groups on condition
that it can be released from the group with which it is engaged in order to be

page_text: passed over another, which necessitates its being able to be easily and surely opened.
and re-closed.
The following arrangements are necessary in order to obtain rapidity and.
safety in the opening and closing of the endless chains, but the arrangement may be
varied according to the kind of chain.
In an endless chain or band with " Galle" links, one of the full links, shown in
section through the axis of the chain in Figure 3, is formed by the union of two-
half links a b, each having a trunnion and one of them, b, terminated by a dovetail
tenon of equal breadth to the link and having a considerable thickness at its
thinnest part. The other, a, is terminated by a symmetrical jaw or mortise in which
the dovetail tenon b can fit exactly sliding along a plane parallel to that of the
trunnions. The tenon is held in its place in the jaw or mortise by a screw V
passing through a thread in the upper spur of the jaw or mortise and penetrating
into a recess formed at a suitable point of the upper face of the tenon b.
.es.
The endless roller chain, Figure 4, is formed of a series of roller trunnions T T
engaging in the recesses of the toothed wheels and connected by checks (or side
pieces) F, the eyes of which are traversed by the axles or spindles of the roller
and each of the cheeks of the movable links is formed of a spring R' R² which,/
its natural position, tends to close or to assume the position shown in dotted
on the drawing. This spring, when once engaged with the trunnion, pr
strongly against the eye of the cheek of the following link engaged with the/
trunnion, an effort proportionate to its tension, exerted from the inside ou
being necessary to cause it to move from this last position in order to of the
endless chain.
For this object, a suitable piece of wood or iron forming an angle or eve
is introduced between the two spring cheeks so as to cause these side/
separate and to cause each eye to come off its trunnion.
S
ne
rds.
finger
ings to.
In order to refasten it, the eye of one of the side cheek springs is f engaged
with one of the trunnions of the roller, then, by pressing strongly on the other spring
cheek, its eye is brought in front of the other trunnion, which engages therein of
itself as soon as the spring cheek is released.
The system of movable cheek spring is also applicable without the slightest
modification to chains with solid links. In this case, instead of the solid link, it
would be the link with cheeks connecting two full links that would open.
In all these systems, after having opened or severed the chain, it is removed from
the set of wheels on which it was engaged in order to be shifted on to the set which
it is desired to operate, and it is then re-closed. This very simple operation scarcely
requires a minute.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In bicycles, tricycles and the like, mechanism for changing the speed,.
consisting of two groups or sets of toothed wheels of different sizes and diameters,
one of these groups being mounted on the pedal axle and the other on the axle of
the driving wheel, the said groups of toothed wheels being in one or more parts,.
substantially as hereinbefore described and shown on the accompanying drawings,
(Figure 1).
2. In the mechanism hereinbefore described, and shown on the accompanying
drawing for changing the speed of bicycles, tricycles and the like, the two cog
wheels B D or b d bolted on the centre cog wheels C or e, together with the
suppression of a part of the spokes of the wheel.
3. In bicycles, tricycles and the like, an endless chain for operating the cog
wheels, this chain being formed of links capable of being instantaneously opened
and closed substantially as described and shown in Figures 3 and 4 of the
accompanying drawing, the said links being characterised by:
(a) In an endless "Galle" link chain, two half links each comprising a trunnion

page_text: and terminated by a dovetail tenon as wide as the link which fits into a
suitable jaw or mortise formed in the other half link, this tenon being held
in position by means of a screw V which passes through a screw thread in
the upper part of the jaw and penetrates into a recess formed in the upper
face of the tenon:
b) In an endless so-called roller chain, Figure 4, formed of roller trunnions T
connected by cheek pieces F, the eyes of which are traversed by the axes of
the rollers, each cheek of the movable link being formed by a spring R¹ R'
which tends to close, and which, when once engaged with the trunnion,
presses strongly on the eye of the cheek-piece of the following link engaged
with the same trunnion.
Dated this. 30th day of April 1894.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.