Improvements in Driving Gear for Bicycles and Tricycles.
Year: 1891

page_text: Date of Application, 15th May, 1891
Complete Specification Left, 15th Mar., 1892-Accepted, 16th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in Driving Gear for Bicycles and Tricycles.
JOHN WILSON of Brothers Street Livesey Blackburn in the County of
Lancaster Builder do hereby declare the nature of this invention to be as
follows:-
Expanding and contracting driving wheel with appliances for taking up and
giving out of chain,
By pulling a lever the wheel becomes expanded for light roads and by the reverse
action becomes contracted for uphill and heavy roads.
The wheel is built in sections and becomes expanded and contracted by means of
a cam put in motion by a lever affixed to handle bar similar to the brake but at
opposite side and the change is effected while the operator is riding.
A section contains two teeth and a wheel may have as many sections as desired
which becomes expanded immediately upon their release from the chain at the hind
part of the wheel. When expanded to their proper position a catch drops in and
holds them firmly and so on until a revolution of the pedal is made when all the
sections have become expanded.
To contract the wheel the lever is reversed withdrawing the catches as the pedal
revolves just at the juncture of each section becoming released from the chain, as
when the expansion takes place.
The degree of expansion is one half of the contracted wheel thus a wheel of
12 teeth expands equal to a wheel of 18 teeth or of 14 to 21 and so on leaving a
tooth out between each section.
It will be noted the sections do not expand and contract gradually during the
full revolution of the pedal or wheel but that the change is fully developed during
the part of the revolution which is released from the chain.
The chain is held in tension by means of a spiral spring, the bearings of the hind
wheel working in slides and when the wheel is contracted the driven wheel travels
backwards in proportion, but the tension may be maintained by means of swinging
bearings for pedals or other means.
Dated this 14th day of May 1891.
JOHN WILSON.
COMPLETE SPECIFICATION.
Improvements in Driving Gear for Bicycles and Tricycles.
1, JOHN WILSON of Brothers Street, Livesey near Blackburn in the County of
Lancaster 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:—
This invention relates to improvements in the driving gear of bicycles,
tricycles and the like and to appliances connected therewith the object being to
make the main driving or gear wheel readily adjustable in size or diameter without
the necessity of the rider dismounting so that the size of the driving wheel can be
varied at the will of the rider according as he requires a greater speed for say riding
on level ground or more power consequently a smaller driving wheel for riding up
an incline, and my invention consists of a main driving wheel which can be
diametrically expanded or contracted and an improved method of mounting the
small or rear wheel of the machine so that such wheel moves nearer to or further

page_text: from the other and so maintains an equal tension on the driving chain whether the
driving wheel is expanded or contracted.
Such being the nature and object of my said invention the following is a complete
description of same reference being made to the accompanying drawings in
which:-
Fig. 1 is a view in elevation of an ordinary bicycle having my improvements
applied thereto.
Fig. 2 is a side elevation of my improved driving wheel, the flange or outside
dise being removed in order to clearly illustrate the improvements, in this view, the
wheel is shewn at its smallest diameter.
Fig. 3 is a similar view to Fig. 2 but in this case the wheel is shewn as expanded
or at its largest.
Fig. 4 is an end elevation of Fig. 2.
Fig. 5 is a detail of one of the segments, triggers and springs shewing the
positions assumed by them when the wheel is contracted.
Fig. 6 is a similar view to Fig. 5 but when the wheel is expanded.
Fig. 7 is a plan view of the trigger or catch detached.
Cast
Fig. 8 is a detail of the appliances for controlling the improved mechanism.
According to this my said invention I employ a main driving wheel 1 mounted
and operated by the pedals and cranks, 2-2, in the ordinary manner. The wheel 1
consists of the boss or nave 3 and the flanges or discs 4-4 the annular ring 5 the
toothed segments 6-6 and the triggers or catches 7-7 for controlling them.
to and forming part of each of the segments 6--6 are the studs 8-8 which are free
to work through holes formed in the annular ring 5 and when the wheel is contracted
(see Fig. 2) the ends of the studs S-8 are received in holes or recesses 9-9 formed
for them in the boss 1 of the wheel, and the teeth remain rigid but when the wheel
is expanded by the segments 6-6 being forced outwards, the ends of the studs 8-8
rest on the ends of the triggers or catches 7--7 which latter are free to move on
their fulcrum pins 11-11 received in holes or bearings in the discs or flanges 4-4
the free ends of the triggers or catches 7-7 are connected to the segments 6-6 by
means of the springs 12-12 that when the segments 6-6 are moved outwards the
springs 12-12 draw the free ends of the triggers 7-7 along with them until the
cross pieces 13 of such triggers rest against the internal diameter of the annular
ring 5 and further movement is prevented, the ends of the studs 8-8 now resting
on the ends of the triggers or catches 7-7 (see Fig. 3) until the cross pieces 13 are
moved (as hereinafter described) towards the centre of the wheel when the
triggers 7-7 are moved on their fulcrums 11-11 until their ends pass from under
the studs 8-8 (see Fig. 2) whereon the springs 12-12 draw inwards the
segments 6-6 and the wheel assumes the position shewn by Fig. 2.
In order to maintain the segments 6-6 and teeth rigid when in the extended
or out position, I cast on each segment 6 small projections 14-14 which move in
slide or slots 15-15 formed in the discs or flanges 4-4.
From the above description it will be seen that the wheel has two working or
driving diameters and in order to enable the rider of the machine to change the size
of his driving wheel at will and without dismounting I employ apparatus constructed
as follows:
It is necessary that when the size of the driving wheel is changed from large to
small the slack of the driving chain 15" should be taken up, and when the wheel is
changed from small to large the chain must be slackened.
mount the rear or small wheel 16 of the bicycle in the links 17 (one on each
side of the wheel 16) and the other ends of these links 17 are mounted at 18 in the
ordinary fork or backbone 19 of the cycle so that it will be seen the small or rear
wheel may be moved nearer to or further from the front or large wheel so varying
the distance between the main driving wheel 1 and the second driver 20. The
amount of movement of the links 17 is limited by the pin 21 fixed in the fork 19
and by the movable stop piece 22 (see Fig. 8) or the pedal bracket 37 may be
hinged or jointed and the bracket pedals and main driver moved so as to maintain

page_text: the required tension on the chain 15" the parts being operated by levers and
connections as herein described.
In order to change the main driver 1 from small to large diameter the rider will.
press the lever 22 mounted on the handle of the machine, and this will by the
chain 23 (working over the pulley 24) and the rod or wire 25 move the lever 26 on.
its fulcrum 27 and the rod or wire 28 will draw the stop piece 22 away from the
link 17 so allowing the wheel 16 to move nearer to the front wheel, and the driving.
chain 15 is consequently slack. The movement of the lever 26 will at the same
time by the link 29 have moved outwards the cam 30 the latter moving on its
fulcrum 31 fixed by bracket to the boss of the wheel 1, the outside surface 32 of the
cam 30 will now press against the projections 14 of the segments 6-6 so that the
latter are moved outwards in succession as the wheel revolves and are maintained
in the outward position as hereinbefore described. It will be seen that the
segments 6-6 are moved outwards before they come in contact with the chain 15"
The
so that the cam 30 has only to overcome the resistance of the springs 12.
lever 22 is kept in the required position by being moved into one of the notches 33.
made in a bracket 34 fixed to the handle of the machine.
When it is desired to change the wheel from large to small the lever 22ª is moved.
out of the holding notch 33 and the spring 35 will move the several parts in the
reverse direction so that the inner face 36 of the cam 30 comes in contact with the.
cross bar 13 of the triggers or catches 7-7 whereon the springs 12-12 draw in.
the segments 6-6 as hereinbefore described. As the chain 15" lengthens on the
driving wheel one being made less the wheel 16 will move away from the front
wheel so taking up the slack.
The limited amount of movement allowed the links 17 and wheel 16 prevents the
chain 15 becoming too slack, or there being too much tension thereon and the discs-
or flanges 4-4 serve also as guards to the interior of the wheel 1.
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 general construction arrangement, and combination of parts constituting
the improved driving wheel which can be expanded or contracted, and as and for
the purpose herein described, and substantially as illustrated by Figs. 2, 3, and 4
of the annexed drawings.
2. The lever 26 link 29 cam 30 in combination with the improved driving wheel,.
as and for the purpose herein described and substantially as illustrated by the
accompanying drawings.
3. The method of and means employed for automatically adjusting the tension on.
the driving chains of bicycles and tricycles as herein described and substantially as.
illustrated by Fig. 1 of the accompanying drawings.
4. Mounting the wheel 16 of a bicycle or tricycle on links such as 17 free to
move on a centre 18 in the backbone or fork 19 and stops such as 21-22 as and.
for the purpose herein described and substantially as illustrated.
Dated this 14th day of March 1692.
Dated this 14th day of March 1892.
By his Agent,
WALTER BRIERLEY,
Bank Chambers, Waterhouse Street, Halifax..