Improvements in or relating to Change Speed Gears for Cycles and the like.
Year: 1899

page_text: Date of Application, 16th May, 1899-Accepted, 7th Apr., 1900.
Improvements in or relating to Change Speed Gears for Cycles
and the like.
A communication from LEON STILMANT, Doctor, of Brussels, in Belgium.
I; ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of London,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
The present invention refers to a device to be applied to bicycles, tandems,
tricycles and the like by means of which the speed can be changed at will with-
out stopping the machine.
This device can be adapted to all velocipedes whether they be chain driven or
chainless, and its application involves no changes in the frame while it offers the
great advantage to the rider of enabling him to vary the speed of his machine,
diminishing it when ascending hills for instance, without the necessity of stop-
ping or even slowing down the movement of the pedals.
This device when introduced into a machine is far from detracting from the
appearance of the machine. On the contrary it adds to its appearance, inasmuch
as more lines of symmetry are introduced, especially in chainless cycles, where
the variation of velocity is produced by the proportion of the gear pinions of the
driving wheel.
This result is obtained by arranging an actuating device, by chain or gearing,
on cach side of the machine; in other words there will be two distinct actuating
devices instead of one, but the proportions of the gears are not the same in the
two cases. They are such that for instance one allows of a travel of 9 metres
per rotation of the crank, while on the other side it will only be one of 3 to
four metres, or about one half of the other; and it is especially the latter gearing
which will be of use in mounting hills. It will be, therefore, possible to greatly
increase speed by means of one device, while by means of the other it will be
possible to ascend heights without any fatigue. In order to be able to employ
one or the other of the gears the actuating or driving wheels are loosely arranged
on the shaft and one or other of them, can, by means hereinafter to be described,
be rigidly combined with its corresponding crank when the machine is ridden.
Of course when descending hills the two wheels can remain loose so that the
machine descends by itself without the rider moving his feet.
In the accompanying drawing is represented, by way of example, one way of
carrying out the invention:-
Figure 1 represents a front view of the device applied to a chain wheel and
the corresponding crank, and
Figure 2 is a section on the line A-B of Figure 1.
The device comprises, on each side of the machine, a curved metallic part a
which is loose on the axle c.
secured to the radial spokes of the chain wheel
This piece a is articulated at its ends, by means of joints d, with two other
parts f, also curved, and inclined towards each other as shown in Figure 1.
027

page_text: These two parts f have at their ends, opposite each other, extensions g, arranged
opposite each other and separated by a space forming a hollow or recess with
shoulders into which enters, when required, a bolt i. The parts f are movable
around their joints d, and are pressed from the inside by a spring blade j, fixed
to the part a.
2
The bolt or locking pin i is arranged on the inner side of the pedal crankl
keyed on the axle c, and is guided by a part fixed on the crank. The upper
end of the bolt is pivotted at m to a small connecting rod n itself pivotted at o
to the arm of a lever p q which is loosely mounted on the axle r of the pedal s.
The pin has an extension 1, the end of which slightly overlaps or extends
beyond the pedal, although it is the same height as the pedal itself. The arm 7
of the lever is provided at its other end with a small rod or extension like
the rod, and arranged in the same manner.
On the guide is fixed a blade spring which is provided at the end with a
stud or pin w which engages according to requirements in holes a or y in the
bolti, according to whether the latter is raised or lowered.
The device is utilised in the following manner-
To insert, for instance, the bolt into the recess h, the cyclist, without stop-
ping, or easing the movement of the pedals, and without removing his feet from
the pedals moves the point of his shoe towards the rod t which, in consequence of
the rotation of the crank comes in contact with the sole of his shoe. In con-
sequence of this movement the lever p q changes into the position, as indicated
by the line cd, and depresses the bolt i, which slides down the crank, like
the bolt in a lock under the action of a key. This bolt moves on pressing
against the corresponding part f and enters the recess, as represented by the
dotted lines (Figure 1), the part f is then raised under the action of the spring j
and the bolt is enclosed by the jaws g. Thereupon the wheel b becomes geared
to the crank until the cyclist releases the bolt by a movement contrary to the
one just described i.e. by pressing with the heel on the rod of the lever arm
(Figure 1) in which case the latter is brought back to its normal position shown
in the drawings, and the bolt withdrawn, the edge of the pin and of the
holes, y being rounded off to allow the pin to slip in and out easily.
It may be observed here that in the construction of new machines, when one
is not bound by the dimensions of an existing machine, the device may be
arranged and made in various modified forms, the arrangement represented by
way of example in the accompanying drawing, being specially intended for
application to an existing machine and requires but slight alterations in the
machine itself.
It should also be observed that the actuating wheels should preferably be
mounted on the shaft e on ball bearings, in order to diminish friction, and
finally it may also be observed that if the cyclist should inadvertently put both
the wheels in action at the same time by gearing them at the same time to their
corresponding cranks no accident could result, since the wheels are loose on the
shaft and the cyclist would immediately become aware of it owing to the slender
speed mechanism acting as a brake on the higher.
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondent and in what
manner the same is to be performed I declare that what I claim is:--
1. A device for changing the speed of cycles and the like while travelling,
comprising two actuating devices of the driving wheel, working by chain or
gearing, the said actuating devices consisting of two sets of wheels and pinions
of the necessary diameters for the purpose of obtaining the required velocities,
and arranged respectively on the two sides of the machine: the said actuating
wheels being rigidly united with or disconnected from their cranks by any suit-
able mechanism substantially as described.
2. In a device of the kind described, an actuating wheel loose on the pedal axle

page_text: provided with a curved part fixed outside the spokes of the wheel, and two curved
blades such as f, articulated to the ends of the latter and terminating at their
upper opposed ends in two extensions with stops forming a recess for the admis-
sion of a bolt or locking pin actuated in any suitable manner and a spring
intended to return and keep in their normal positions the curved movable pieces,
substantially as described.
3. In a device of the kind described a bolt or locking pin in combination with
the crank and suitably guided on said crank so as to be longitudinally movable
thereon, a spring catch to hold the bolt in any required position, a connecting
rod hinged at one end to the bolt so as to actuate the latter and at the other end
to a lever pivotted on the pedal shaft, said lever being provided with two exten-
sions arranged one in front and the other behind the pedal so as to be actuated
by the foot of the rider, in order to raise or lower the bolt substantially as
described.
4. The complete device for changing the speed of cycles and the like while
travelling substantially as described or illustrated in the accompanying drawings.
Dated the 16th day of May 1899.
BOULT & WADE,
Agents for the Applicant.