Improvements in Driving Gear for Cycles and the like.
Year: 1895

page_text: Date of Application, 17th Dec., 1895-Accepted, 15th Feb., 1896
COMPLETE SPECIFICATION.
Improvements in Driving Gear for Cycles and the like.
I, ETIENNE PLACIDE LOUIS MARIE VERDOT, of 45, Rue Laugier, Paris, in
the Republic of France, Machine Builder, 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 :-
The motion of the pedals of cycles is generally transmitted to the driving wheel
by means of a chain, the many drawbacks of which arrangement have led to
attempts which have been made with a view to finding a suitable substitute for the
usual driving gear, wherein the chain is altogether dispensed with.
Now the present invention consists in substituting for the chain driving gear a
combination of parts or devices, both simple and light, the employment of which
offers many important advantages.
The invention will be best understood by reference to the accompanying drawings
in which the general arrangement and combination of the devices, which are
employed in carrying out the invention, are illustrated by way of example;
Figure 1 is a side elevation of the complete arrangement;
Figure 2 is a plan of the same; and
Figure 3, a side elevation of a velocipede provided with the improved driving
gear; while
Figures 4 to 7 are diagrams showing modified arrangements of the pulleys.
By referring to the drawings, it will be seen that the improved driving gear is
double, that is to say, the driving wheel of a bicycle is operated on both sides at
the same time.
A is the pedal or crank axle upon which two grooved pulleys B B' are mounted
within the space between the pedals C C¹.
Upon the horizontal tubular cross-pieces D D¹, connecting the pedal arrangement
to the axle of the driving wheel E, are soldered sleeves F F¹ forming ball-hubs for
the double-groove pulleys G G. For the pinion usually keyed on to the driving
wheel axle, grooved pulleys H H' are mounted laterally on either side. The grooves
of the pulleys B B and H H' are internally lined with india rubber, to ensure the
tight adhesion or frictional contact of the driving cable or cord.
The operation of the improved mechanism is very simple and may be briefly
described as follows:
As the pedals revolve the pulleys B B in the direction of the arrows, the
portions a and b of a cable or cord-shaped strap of any suitable material, are driven
in the direction of the arrows thereon.
The portions a of the said cable, as they leave the pulleys B, pass on to the
grooves H H', respectively, covering about three quarters of their circumference ;
hence they pass on further to the grooves d of the pulleys G G', and then around
the pulleys B B', covering two thirds of the peripheries of the same.
It will be understood that the intermediate pulleys G G serve to cause the
portions a of the driving cable to cross or intersect, and thereby to add to the
tightness of adhesion or friction between the rope and the grooves of the pulleys B B¹
and H H. The proportion of the respective diameters of the pulleys ensure the
desired multiplication of speed.
The object of the double-groove pulleys G G¹ is to counteract friction between
the portions of the cable intersecting at X X.

page_text: More than one length of cable may be employed, if necessary, on either side;
and the axle of the driving wheel and, consequently, of the pulleys H H¹ also,
may be fitted with any convenient tension controlling or adjusting mechanism, so
as to provide a remedy in case the cord should become either loose or over-
strained.
In order to reduce the weight of the pulleys, they are preferably constructed of
aluminium; and their grooves may, if need be, have embedded in them some
material capable of promoting the close adhesion of the cable or cord.
The advantages of the improved driving gear need not be further demonstrated,
as they may be summarily and clearly expressed in three words: lightness, safety
and moderate cost.
The improved driving gear may, if preferred, be applied to one side of the
machine only.
The details of the construction of the novel cable or cord driving gear may, of
course, be modified to suit special requirements without departure from the principle
of the invention.
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. The employment, in lieu of toothed wheels, pinions, or the like, of grooved
pulleys adapted to carry round with them by adhesion or friction a cable or cord
of any suitable material, substantially as described.
2. The intermediate pulley having twice as many grooves as there are lengths
of cable to carry round; such pulley being adapted the better to guide the cable
round the driving pulleys, and to cause it to tightly adhere thereto.
3. The arrangement of driving pulleys on either side of the pedal mechanism of
the driving wheel, such arrangement enabling oblique side strains to be avoided
and consequently protecting the frame of the machine from being overstrained,
while at the same time ensuring a better driving or motion-transmitting effect
substantially as described.
4. The employment of grooved pulleys lined with any suitable material capable
of increasing the adhesion, or tightness of frictional contact, of the cable,
substantially as described.
Dated this 17th day of December 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.