A New Propelling Mechanism for Cycles.
Year: 1896

page_text: Date of Application, 6th Mar., 1896-Accepted, 9th May, 1896
A New Propelling Mechanism for Cycles.
I ROGER, BARON OF MAUNI, of Croisset, near Dieppedalle, Department of
Seine-Inférieure, France, Inventor, 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 consists essentially in the replacing of the crank and pedal which:
are now used as propelling appliances for cycles, by a strap and a stirrup or non-
revolving treadle or pedal, the said strap gradually diminishing in thickness from
the stirrup end to the other end, and being enrolled on an eccentric barrel, the
effect of such diminution of thickness of the strap, combined with the eccentricity
of the barrel, being that the radius or leverage on which the muscular strength of
the cyclist has to act diminishes from the beginning to the end of the leg's stroke ;
further, in the same strap's being able to enroll and contract itself automatically as
soon as left alone; and finally, in the combination of the above contrivances with
the optional lifting or lowering of the fore part of the gear without stopping or
dismounting.
The stirrup is made out of a pure nickel sheet, but could be made also of plated
steel or iron or any other metal. It may affect various shapes; the one which we
have made resembles an Arab or Turkish stirrup, and has a rather large sole.
The subjoined drawings are all in real size, excepting No. 4 which is at the scale
of one fifth, or say twenty centimeters for one meter. They are all meant for a
tricycle. Besides, it is easy to imagine how my system could be applied to bicyclettes
of any pattern.
The strap has a length of from fifty to eighty centimeters, according to the
cyclist's size. It is fastened by its thinner end on the drum or barrel, in the very
place where the said drum has its maximum radius, and then is rolled up on the
barrel and on itself, so as to present the shape of a spiral. Thus, supposing the
maximum radius of the barrel to be four to five centimeters, and the maximum
thickness of the strap to be six centimeters, one sees that when the strap is
completely rolled up, the power arm acting on the stirrup is ten to eleven
centimeters, and then gradually diminishes to four whilst the strap gets unrolled.
The minimum thickness of the strap is counted for nought, as the drum or barrel
is notched at the fastening place so as to leave no vacuum in the spiral.
As is shown by Drawing No. 1, the upper end of the stirrup has two eyes or holes,
and is tied to the external edge of the strap's thickest end by means of a bolt which
passes through the said eyes. The upper face of the strap is made out of a leathern
band, or of other flexible and inextensible stuff, and the end of the band is stitched
round the bolt aforesaid.
The drum or barrel is made of steel, and ought to be hollow. It is fitted on the
outer part of the cog-wheel's axle, by means of a ball bearing, and is allowed to
turn freely backwards, but prevented from turning forward by a small ratchet
wheel. The said ratchet wheel is wedged on the axle, and is caught by a click and
spring fitted on the side of the drum, and both are sheltered under the protruding
circumference of the drum. Or, on the contrary, the circumference of the drum
may be indented inside, and the click and spring may be fixed on the axle. Anyhow,
the drum when drawn forward draws the axle, the chain and the whole gear, and
when drawn backwards turns alone, the only and very slight check then imparted
to the continued propelling of the machine consisting of the little dead work done
by the click and ratchet.

page_text: Of course, the eccentricity of the barrel could be increased, and the gradual
thickness of the strap could be lessened, or vice versa: these two things concur to
the same end, and the prominence given to one dispenses, at.least partly, from the
other but one sees that making the strap alone, or the barrel alone, enormous,
would not go without many practical inconveniences, on the details of which it is
unnecessary to insist.
Drawing No. 1 shows the strap and barrel and the upper part of the stirrup as
they appear when the machine is at rest, or when the cyclist's foot is lifted. The
machine is supposed to be seen as rolling or about to roll from the left towards the
right of the reader.
Drawing No. 2 shows the drum and part of the strap when the latter is extended,
the cyclist's foot being then as low and his leg as stretched as possible. It has
been deemed useless to show the whole length of the strap, the part shown on,
Drawing No. 2, when compared with Drawing No. 1, being quite sufficient to give a
correct idea of the manner in which it is made. A, A', A", &c., are small bits of
wood, or impregnated cork, or hard black rubber, or any similar stuff, which are
arranged and screwed under the leather band. B, B1, B", &c., are the vacua or
hollow spaces which are caused to appear between A and A', A' and A", and so
on, when the strap is being stretched out, and these vacua disappear and are filled
one after another, as soon as the strap is being rolled up. Therefore on Drawing
No. 1, which shows the strap when rolled up, nothing is seen of B, B, B", &c.,
whilst A, A, A, &c., are drawn close together and fill up the whole of the spiral.
One sees that each of these bits must be different from the next one and from all
others both in shape and thickness. They are arranged just as the chine-bones of
a snake, and are doing the very same duty.
Now the drawings show only the skeleton of the snake; but our strap, playing
the part of a snake, ought to have a skin, and that skin ought to be elastic. It is
made of pure flat india rubber sheet, and is shaped as a sort of purse or bag, which
envelopes the whole system and is perfectly adjusted on it. That purse or bag,
when left alone on a table, lies rolled up in the shape of a snail's shell, so as to
include exactly all the bits or bones, and keep them pretty tight against each other
as shown on Drawing No. 1. Then it is easy to conceive that, the strap being thus
fitted out and enrolled on the drum, a sufficient force applied on the outer end of
the strap may draw it and stretch it out; but as soon as the said force ceases to
act, the strap must obey to the tension of its skin and roll itself up again and make
the drum turn backwards until the whole system has retaken its spiral form.
The leather and the rubber sheet are fastened on each of the chine-bones with
light brass or iron screws and rundles, which are screwed on the out or upper side,
or we may say on the back of the snake. On the other sides we deem better to
dispense with fastenings as completely as possible, in order to allow the bones to
play freely on each other, and to avoid the pinching or tearing of the skin. The
said skin ought, however, to be pierced with some small and scarcely perceptible
holes, so as to permit the air to Bow into the vacua when formed and to be quickly
expelled out of them when they are being filled up. It may also be useful to
powder the interior of the rubber skin, just as we do a pair of new gloves, in order
to prevent frictions inside.
Instead of the above described rubber skin, a single band of strong elastic rubber
sheet, laid on the small ends of the chine-bones, would suffice to give us the same
result, provided the said band be capable of a sufficient tension: but then a free
access between the bones would be opened to dust and stones. That band ought
to be fastened under each bone, in order to prevent its going athwart. Another
inconvenience of the single tension band is the possible twisting of the snake when
suddenly left to itself.
Again, the whole spiral may be cut out of a single plate of elastic rubber, without
any bits, or bones, or skin. It would then consist of only two parts, viz. the solid
rubber spiral, and an inextensible atrap laid on the outer part of the said spiral, in
order to allow the stretching out only of its inside face, the advantages then being

page_text: simplicity and strength, and the inconveniences, compressibility and a rather heavy
weight.
The self-contracting of the snake may be facilitated by means of a spiral band of
steel, which should be joined with the leather, and thus render it quite inextensible.
We have had a pair of straps made out simply of a full rubber spiral fitted outside
with a steel band rolled up as a clock spiral and thus acting as a spring, which has
proved satisfactory.
It ought to be noticed that when in working order, the strap ought never to be
quite stretched out as shown on Drawing No. 2, but some part of it must always
remain enrolled on the drum, so as to secure its swiftly running up and enrolling on
the said drum as soon as the foot ceases to press on the treadle.
There is another piece or part of our system, which is shown only on Drawing
No. 4. It is, simply, a circular screen or shield, made of nickel sheet, polished and
adorned with sune engraving outside. The said screen is pierced with a central
hole, and fastened on the end of the axle with a plated screw. Its duty is to shelter
and cover the side of the spiral, also the ratchet wheel, click and spring, and to
preserve them from dust and from outside blows, and, finally, to give the whole
gear a clean and rather elegant appearance. Further, it forbids the strap's going
athwart whilst being stretched out or rolled up.
The breadth of the strap, and consequently of the drum or barrel, may be from
one to two inches. The outside half of the drum shelters the ratchet wheel and
click, whilst the other half, that nearest to the cog-wheel, is filled by the ball bearing
and its regulating cone.
The frames of the machines thus geared may vary according to fancy or convenience.
Of course, the now prevailing frame should be slightly altered. Thus, the cog-
wheel axle, usually termed crank axle, ought to be hung up higher than heretofore,
and the forward part of the chain has to be lifted accordingly, which will prove of
great advantage for its preservation from mud, dust and stones. Now one conceives
that the chain ought to be kept quite clear of the framework, and that the
combinations which may bring to that result are infinite in number. The most
elegant and convenient frame as appeared to us consists of a single strong tube,
forming a sort of bow or arch which connects the fore and after parts of the
machine (see Drawing No. 4). The propelling gear as above detailed hangs from
that main bow or backbone, at a distance of ten to twenty centimeters from the fore
crown.
There remains to be described the special appliance by means of which the whole
propelling gear can be lifted or lowered at the cyclist's pleasure. It is shown on
Drawings No. 3 & 4. The cog-wheel axle, which drives the chain, and has to
sustain the whole pressure of the cyclist's weight and power, sits upon two strong
ball bearings right and left, and it is these bearings or boxes which hang from the
main bow or backbone. They are connected with the said backbone or main tube
by two flat steel rods or slides. These slides are not straight but curved, as shown
on Drawing No. 4. The curve they describe is part of a circular circumference,
the supposed centre of which is on the centre line of the after wheels axle, and the
radius equal to the distance between the said centre line and that of the cog-wheel's
axle. These curved rods are about twenty-five to thirty centimeters in length,
They are slit, from the lower third of their height close to their upper end, the slot
being thus about sixteen centimeters long, and one centimeter wide. Besides that
one of the two rods, say the left hand one, is edged outside in the shape of a square
gutter. Now, at the very point where the ideal circumference just specified cats
the main tube, the said tube is strengthened with a welded bush, and the tube and
bush are pierced through, so as to allow the passage of a screw bolt of about
one centimeter thickness. The passage hole must show an elliptic or lengthened
section, in order to allow the regulating of the chain. The bolt passes through
hat hole and through the slots of the two rods; its head presses on the flat rod,
and its nut, which is square edged, is drawn on the other side into the gutter, where
t may move upwards and downwards but not turn. The bolt's head is fitted with

page_text: a small crank handle, the turning of which causes both rods either to become loose,
or on the contrary to be jammed against the backbone's bush. The upper ends of
these hanging slides or rods are connected by a bit of strong tube, in order to
permit the cyclist's hand to take a good hold of the gear, and lift it up or allow it
to drop gently, which practically means increasing or diminishing instantly the 5
machine's multiplication: for, as the snake is nearly one half longer than is
necessary for an ordinary stroke of the leg, one sees that if acting on its thicker
part the leg's stroke will give power, and if acting on its thinnest half or two thirds
will furnish speed, and the change will be effected without dismounting or stopping,
by a simple movement of the hand.
In order to give the whole gear the necessary stiffness, the bearings of the cog-
wheel's axle are further connected, by two straight rods, with the axle of the after
wheel or wheels. The after ends of these two rods are strengthened and widened,
and show, on that wider part a broad slot, which needs being only long enough to
allow the regulating of the chain's tension. The slot embraces a ring, which plays
around the after axle, by means of a ball bearing, and which shows at its after end
a wormed bit which is drawn from outside by means of a thumb nut. The above
details may be seen on Drawing No. 4. It is easy to see that the lifting or lowering
of the gear may thus take place a hundred times one after another without altering
the tension of the chain or bringing any strain on the gear.
The stirrup has been allowed a rather great length, in order to prevent the
interfering of the gear with the free movement of the cyclist's knee. Its upper
part is shaped so as to adjust and prop itself against the spiral when rolled up,
which, as one may easily see, gives an additional leverage power on getting under
way, by simply bending one's toes.
The numerous advantages of the above described system need not to be dwelt
upon at length. The cyclist enjoying a free stroke of the leg, is enabled to stamp
down at full speed and then to lift his foot slowly, and to have a long or a short
stroke, just as he pleases: any amount of muscular work done is turned to account
and benefits the propelling of the machine, whilst the lifting of the foot and leg in
the usual crank and pedal system entails a tremendous loss of force, as has been
shown recently by the experiences of Professor Marey, of the French Institute.
Further, the dead point and its inconveniences are totally abolished. The cyclist's
putting one foot or his two feet on the soil, in order to stand upright when stopping
or going dead slow, or on the contrary, when running too fast in order to slacken
or to stop, is no longer prevented by the implacably turning crank and pedal.
Further, as any one can see, the cog-wheel's axle's maximum length, with its two
bearings and two drums, scarcely exceeds fifteen centimeters, and, as the stirrups
hang perpendicularly under the drums, it is clear that no existing machine can
afford such a close proximity of the two feet. Now all the above advantages, or
nearly all, could be obtained with an ordinary drum and an ordinary strap,
combined with a ratchet wheel, which sort of contrivance was known long ago:
but then they would be counterbalanced by the necessity either of making the
drum enormous, or of taking up with a very short power arm. These inconveniences
we have suppressed by the combination of our conical or rather pyramidal strap
with a small round or rather moderately eccentric drum, and we have added the
enormous benefit consisting in the leverage's decreasing from the beginning to the
end of the leg's stroke, which wonderfully agrees with the peculiar necessities of
muscular propulsion. Finally, the problem of changing at will power against speed
and vice versa, which has been so long vainly sought for, is definitely and completely
solved in the most elegant and simplest manner.
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 1
claim is :-
First. The adaptation to the cog-wheel axle of cycles of a strap, diminishing in
thickness from its lower end to its upper end, and self contracting and enrolling,

page_text: in lieu of the cranks now in use, the features of novelty of the said strap being its
varying thickness and its self-contracting;
Secondly. The combining of the said gradually diminishing and self-contracting
strap with an eccentric drum or barrel, on which the strap is enrolled and which
when drawn forward causes the driving axle to turn, and when pushed backwards
becomes loose upon the said axle ;
Thirdly. The combining of the two aforesaid appliances with a stirrup or non-
revolving treadle or pedal, in order to propel the velocipede by muscular force,
and to apply that muscular force on a gradually diminishing leverage or
power arm;
Fourthly. The combining of the contrivances aforesaid with the instantaneous
lifting and lowering at will or pleasure, by means of slides as described, of the cog-
wheel and axle and gear attached, so as practically to allow the easy changing at any "
moment and to any degree of the respective proportion of power and speed in the
actual working of the machine, without stopping or dismounting, the novelty
here, as in the second and third paragraphs of claim, consisting in the
combination.
Dated this Fifth day of March 1896, at Croisset, near Dieppedalle, Dept. of
BON. DE MAUNI.