An Improved Chain and Pinion for Velocipedes.
Year: 1893

page_text: Date of Application, 27th June, 1893
Complete Specification Left, 7th Dec., 1893-Accepted, 10th Feb., 1894
PROVISIONAL SPECIFICATION.
An Improved Chain and Pinion for Velocipedes.
I, JEAN BARDET, of 39 Rue Bouret, Paris, in the Republic of France, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to a chain and pinion designed for transmitting the motion
of the pedals to the driving wheel of velocipedes and are designed to replace the
types of chains and pinions heretofore employed in such vehicles.
The improved chain comprises only two types of parts, that is to say rectangular
links the transverse parts of which form interiorly a rounded knife-edge and spiral
springs for connecting the said links, these springs being made of square, rectangular
or other wire the convolutions of which touch each other.
In order to compose the chain I bring two links together, put the spring on the
side of these links open the first convolution and then turn the spring, the operation
being effected in a similar manner as a key is put on a slit ring. The spring adapts
itself by reason of its elasticity. In like manner the third, fourth and every
further link is mounted, whereupon the chain is closed by uniting the first and last
link.
This chain possesses the following advantages.
(1) Being mounted without riveting it may be made of hardened steel which
gives it a considerable resistance to wear and enables it to be made very light, the
material acquiring a very great strength by the hardening.
(2) It moves with the least friction, the transverse portions of the links rolling in
the interior of the springs after the manner of the kuife-edges of a balance,
which result is obtained by the particular form given to the pinions hereinafter
described.
(3) The chain may be repaired on the way; when a link is broken it may
be replaced immediately if the cyclist takes care to keep some reserve parts in his
pocket.
(4) This chain can move in dirt and dust, owing to the large free space between
the spring and the link and because no sliding friction is produced when the chain
is bent, but a rolling movement upon the knife edge.
(5) It is composed of only two kinds of parts, which is a very great advantage
as regards the manufacture.
(6) It may always be readily dismounted for ascertaining the friction.
(7) It has, like the ordinary chain two bending axes for one element of the chain,
which is an advantage as compared with the chain having rollers.
I may stamp, punch or cast the links of this chain and make them of hardened
or non-hardened steel or any other material, and I may manufacture them in any
desired manner and use any suitable material for the springs.
For ensuring the rolling movement of the chain upon the driving pimons it
is necessary to place the links and springs upon the pinion in such a manner that
the line which joins the knife-edges of the two cousecutive links may be a diameter
of the spring.
Each link bears exteriorly on the cheeks of the teeth of the pinion and the spring
on the bottom part of the teeth.
During the rolling movement of the chain the links remain in a straight line with

page_text: the spring, which turns upon the edge of the link and bears upon the bottom part
of the teeth when the whole has described half the angle of that which two
consecutive links form. The link continuing to turn bears upon the edge which
forms two consecutive sides of the same cheek. The chain is in the state of stable
equilibrium upon the pinion, because the forces by which the different parts are
actuated are perpendicular to the bearing surfaces.
In a modification of the above described pinion the part which receives the ring
extends across the pinion. This arrangement may be employed in all cases where,
the number of teeth being sufficiently great, the angle made by the link with its
support upon the ring will be smaller, at the moment when it bears upon the edge
of the link, than the tangent of the angle of friction, which condition will be
fulfilled when the pinion has at least eight teeth.
Dated this 27th day of June 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
שת
An Improved Chain and Pinion for Velocipedes.
I, JEAN BARDET, of 39 Rue Bouret, Paris, in the Republic of France, 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 relates to a chain and pinion designed for transmitting the motion
of the pedals to the driving wheel of velocipedes and are intended to replace the
chains and pinions heretofore employed in such vehicles.
In the accompanying drawing,
Figure 1 is a longitudinal section through the axis of the chaiu j
Figure 2 is a plan of the chain partly in section;
Figure 3 is a side elevation partly in section of the pinion with the chain wound
thereon ;
Figure 4 is a plan of the pinion and
Figure 5 a plan of a modification of the said pinion.
The improved chain comprises only two series of parts, that is to say the parts A
in the form of hollow rectangles, the transverse parts a of which are interiorly
shaped to the form of a rounded knife edge, and the parts B for connecting the
said links, which consists of square, rectangular or other wire, the convolutions of
which touch each other.
In order to mount the chain I bring two links A together, put the spring on the
side of these links, open the first convolution and then turn the spring, the operation
being effected in a similar manner to that in which a key is put on a slit ring.
The spring adapts itself or closes up by reason of its elasticity.
The other links of the chain are mounted in like manner, whereupon the chain is
closed by uniting the first and last links.
The improved chain possesses the following advantages:
(1) Being mounted without riveting it may be made of hardened steel which
gives it a considerable resistance to wear and enables it to be made very light, the
material acquiring a very great strength by the hardening process.
(2) It moves with the least friction, the transverse portions a of the links A
rolling in the interior of the springs B after the manner of the knife-edges of a
balance, which result is obtained by the particular form given to the pinions herein-
after described.
(3) The chain may be repaired on the way; when a link is broken it may be

page_text: replaced immediately if the cyclist takes care to keep some reserve parts in his
pocket.
(4) This chain will operate notwithstanding the presence of dirt and dust, owing
to the large free space between the spring and the link A and because no sliding
friction is produced when the chain is bent, the said chain moving with a rolling
movement upon the knife edge.
(5) It is composed of only two kinds of parts, which is a very great advantage
as regards the manufacture.
(6) It may always be readily dismounted for ascertaining the amount of wear
the chain is subjected to.
(7) It has, like the ordinary chain, two bending-axes for one element of the
chain, which is an advantage as compared with chains having rollers.
I may stamp, punch or cast the links A of this chain and make them of hardened
or non-hardened steel or any other material, and I may manufacture them in any
desired manner and use any suitable material for the springs B.
For ensuring the rolling movement of the chain upon the driving pinions it is
necessary to place the links and springs A and B upon the pinion in such a manner
that the line a' as which joins the knife-edges of the two consecutive links may be
the major axis of the spring.
Each link A bears exteriorly on the cheeks C of the teeth of the pinion and
the spring B on the bottom part d' of the space between the teeth d.
During the rolling movement, the chain being in the position A, Figure 3, and
the link A being supported, the spring is in the position B'. As it continues to
move the links A' remain in a straight line with the spring, which turns upon the
edge of the link A and bears upon the bottom part of the teeth when the whole
has described half the angle of that which two consecutive links A form with each
other.
At this moment A¹ has arrived at A' and B₁ at B2. The link A continuing to
turn bears upon the edge c² which forms two consecutive sides of the same cheek.
It then moves into the position A³ and the same operation is repeated in the
movement of the following link. The chain is in the state of stable equilibrium
upon the pinion, because the forces by which the different parts are actuated are
perpendicular to the bearing surfaces.
Figure 5 represents a modification of the above described pinion which consists
in that the part which receives the ring extends across the said pinion, thus
dispensing with the support c³. This arrangement may be employed with oval
springs, but with springs of circular form it is possible only in cases where the
number of teeth being sufficiently great, the angle made by the link A with the
normal of its support upon the ring is smaller, at the moment when it bears upon
the edge of the link, than the angle of friction corresponding to the materials of
which the chain and pinion are made, which condition will be fulfilled when the
pinion has at least eight teeth, this angle being 360 degrees. This arrangement
moreover is optional.
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
First. An endless chain for transmitting motion in velocipedes, bicycles, tricycles
and the like composed of links A of rectangular form and rings formed of helical
springs B preferably of oval form and whose convolutions, which touch each other,
are wound round the short sides a in the form of rounded knife edges for connecting
two consecutive links without riveting and by a rolling movement of the sides a' of
the said links A upon the inner parts of the rings B; the links A and the rings B
being combined with correlative projecting parts c and hollow parts c' and d¹ of
the wheels and pinions for the transmission of movement.
Second. In combination with the transmitting chain described in the first claim,
the modification of the wheel and pinion by which the cavity d' which receives

page_text: the connecting ring B extends through the whole thickness of the pinion or of the
wheel as described with reference to Figure 5.
Dated this 6th day of December 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.