Year: 1895

page_text: I, WILLIAM HUNTER MILLER, of 8 Belvidere Terrace, Paignton, in the County of
Devon, Gentleman, do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in means for varying the ratio between the
diameter of the chain wheels in the chain driving gear of cycles, so that the machine
may be geared higher or lower within certain limits, at the pleasure of the rider, and
the main object of my invention is the construction of a gear of this class, which can
be varied without it being necessary for the rider to dismount, or stop the machine.
The apparatus which forms the subject of my invention, consists substantially of
means, for altering the diameter of the chain driving wheel on the pedal spindle, for
altering the position of such spindle to take up the slack of the chain in accordance
with the altered diameter of the chain wheel, of a special form of chain, and of
appliances for effecting such alterations by the rider, without dismounting or bringing
the machine to rest.
The chain wheel on the pedal spindle, consists of a disc, keyed thereon and having
radial slots, in which arms are adapted to slide carrying the chain teeth on their outer
ends. A disc, capable of rotation on the spindle, has a scroll cut on one face, and
teeth on the aforesaid arms engage with the said scroll, so that by the rotation of the
disc the arms can be advanced or retracted to enlarge or reduce the acting diameter
of the wheel, somewhat after the manner of a self-centreing scroll chuck for a
lathe.
The bearings of the pedal spindle slide in horizontal guides, affixed to the frame of
the machine, in order to accommodate the chain to the varying sizes of the wheel,
and thus keep it at the correct tension.
A shaft, terminating at one end, near the handle bar of the machine, in a crank, or
other like device within convenient reach of the rider, is connected at the other end by
suitable gearing with one or more screws, threaded through the pedal spindle
bearings, so that by rotating the said shaft, the pedal spindle can be moved along the
aforesaid guides.
Upon the pedal spindle is a loose sleeve, a coiled spring has one end connected to
the said sleeve and the other end to the aforesaid scroll disc, and a brake of any
suitable description is provided to act upon this sleeve.
The action of the apparatus is as follows; Assuming the chain wheel to be at its
largest diameter, the pedal spindle is necessarily at that end of the guides nearest to
the driving wheel of the machine, if it is now desired to gear the machine down, the
rider turns the shaft aforesaid, which moves the pedal spindle along its guides. The
aforesaid brake is so arranged that this motion causes it to act upon the aforesaid
loose sleeve, to retard or stop the rotation of the scroll disc, and the pedals continuing
to revolve, the arms aforesaid are drawn in; when the desired ratio of gear is reached
the forward motion of the spindle in the guides is stopped, the brake is released and
the scroll disc then rotates with the spindle as before, the chain wheel remaining at
its altered diameter.
To enlarge the said wheel again, the pedal spindle is moved back, and the scroll
disc is caused to rotate to extend the arms, by means of the aforesaid coiled
spring.
An indicator may, if desired, be combined with the bandle, or other device by.

page_text: which the rider operates the mechanism, to shew when the different ratios of gearing
are obtained, and audible signals may be combined with the said indicator for use at
night.
At certain diameters of the chain driving wheel, the chain will not gear correctly
with the teeth thereon, I therefore prefer to employ a chain, consisting of plates
hinged together and having slots, in which loose rollers can work, so that any roller
coming in contact with the top of a tooth will merely be pushed up out of the way.
The teeth on the chain wheel of the driving wheel of the machine, are, in this case,
made of such depth, as to take the said rollers when at the bottom of their slots.
Or, as an alternative arrangement, the chain may be provided with bars or rollers
on each side exterior to the plates carrying the aforesaid loose rollers, such bars or
rollers being carried by plates or other suitable devices,, while the driving wheel
chain wheel is furnished with a double set of teeth to engage with the said bars or
rollers, the said loose rollers passing between the said teeth.
The above description gives a general idea of the principle of the apparatus forming
the subject of my invention, but various modifications may be made in the said
apparatus, to adapt it to the varying conditions, which may follow its application.
Dated this 31st day December 1895
AMBROSE MYALL,
2 Lancaster Place, London, W.C., Agent for the Applicant.
Improvements in Speed Gearing for Cycles.
I, WILLIAM HUNTER MILLER, of 8 Belvidere Terrace, Paignton, in the County of
Devon, Gentleman, 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 improvements in means for varying the ratio between the
diameter of the chain wheels in the chain driving gear of cycles, so that the machine
may be geared higher or lower, within certain limits, at the pleasure of the rider, and
the main object of my invention is the construction of a gear of this class, which
can be varied without it being necessary for the rider to dismount, or stop the
machine.
The apparatus which forms the subject of my invention consists substantially of
means for altering the diameter of the chain wheel on the pedal or crank spindle, of
means for altering the position of such spindle so that the chain may always remain.in
correct tension notwithstanding the increase or decrease in diameter of the said chain
wheel, of a special form of driving chain, and of appliances enabling the rider to effect
the above alterations as desired, without dismounting, bringing the machine to rest, or
even slackening speed.
The aforesaid chain wheel on the crank spindle, consists of a disc keyed, or other-
wise fastened thereon and having radial slots, in which arms, having chain teeth on
their outer ends, are adapted to slide. A disc, capable of rotation on the spindle, has
a scroll cut on one face, and teeth on the aforesaid arms engage with the said scroll,
so that by rotating the disc the arms can be extended or retracted to enlarge or reduce
the acting diameter of the wheel, after the manner of a self-centreing scroll chuck for
a lathe.
The bearings of the crank spindle slide in or upon horizontal guides, affixed to the
frame of the machine, in order to accomodate the chain to the varying sizes of the
wheel and thus keep it at the correct tension.
A shaft terminating at one end near the handle bar of the machine, or other

page_text: convenient place, in a crank or other suitable device within reach of the rider, is
connected at the other end by suitable gearing and connections with one or more
screws, threaded through attachments on the crank spindle bearings, so that by
rotating the said shaft, the crank spindle can be moved along the aforesaid guides for
the purpose described.
Upon the crank spindle is a sleeve, affixed to or formed upon the aforesaid scroll
disc, so that it rotates with it, a coiled spring has one end connected to the said
sleeve and the other end to the aforesaid radial slotted disc, and a brake of suitable
any
description is provided to act upon this sleeve.
The action of the apparatus is as follows; Assuming the chain wheel to be at its
largest diameter, the crank spindle is necessarily at that end of the guides nearer to
the driving wheel of the machine, if it is now desired to gear the machine down, the
rider merely turns the shaft aforesaid, which moves the crank spindle along the
guides. The aforesaid brake is so arranged that this motion causes it to act upon
the aforesaid sleeve to retard or stop the rotation of the scroll disc, and the cranks
continuing to revolve, the arms aforesaid are moved round the scroll and drawn in
When the desired
and the aforesaid coiled spring is at the same time wound up.
ratio of gear is reached the forward motion of the spindle in the guides is stopped, the
brake is automatically released from the sleeve and the scroll disc then rotates with
the spindle and radial slotted dise and arms as before, so that the chain wheel thus
remains at its altered diameter.
To enlarge the said wheel again, the crank spindle is moved back, this produces a
slack in the driving chain, which leaves the scroll disc free to be automatically
rotated on the spindle by the action of the coiled spring in a direction to extend
the arms.
An indicator may, if desired, be combined with the handle, or other device by
which the rider operates the mechanism, to shew when different specific ratios of
gearing are obtained, and audible signals may be combined with the said indicator for
use at night.
any
At certain diameters of the chain wheel, an ordinary chain would not gear correctly
with the teeth thereon, I therefor employ a chain, consisting of pairs of plates hinged
together and having vertical slots in which loose rollers work, so that roller
coming in contact with the top of a tooth will merely be pushed up out of the way.
The teeth on the chain wheel of the driving wheel of the machine, are, in this case,
made of such depth, as to take the said rollers when at the outer ends of their
slots.
As an alternative arrangement, the chain may be provided with bars or rollers on
each side exterior to the plates carrying the aforesaid loose rollers, such bars or rollers
being carried, if necessary, by plates or other suitable devices, and the driving wheel
chain wheel is furnished with a double set of teeth to engage with the said bars
or rollers, the aforesaid slotted plates and loose rollers passing between the said
teeth.
The above description gives a general idea of the principle and mode of construction
of the apparatus forming the subject of my invention, but various modifications may
be made in the said apparatus, to adapt it to the varying conditions which may follow
its application.
As an example of such application, I will now proceed to describe in detail, with
reference to the accompanying two sheets of drawings, which form part of this
specification, a construction of the apparatus adapted to be applied to an ordinary
safety "bicycle.
In the said drawings:-
--
Fig. 1 is a side elevation of the frame of the bicycle and the said apparatus.
Fig. 2 is a plan of the gear indicator.
Fig. 3 is a side elevation, to an enlarged scale, of the expanding chain wheel and
brake.
1
+
"
2

page_text: Fig. 6 is a full sized elevation of a couple of links in the driving chain.
Fig. 7 is a cross-section of the chain through B B and
Fig. 8 is a top plan of same,
Similar letters of reference denote similar parts throughout the drawings.
The frame shewn in Fig. 1 is of the ordinary "Humber" safety pattern, the only
alteration being that a rectangular shaped box or casing C is substituted for the usual
crank-bracket, the ends of the tubes D, E, F, being brazed into sockets provided on
the said box, in the usual way.
His the crank spindle, running in ball bearings, provided with means for adjust-
ment, in a tube J. K, K, are two parallel rods secured in the ends of the box C,
and L L are projections on the tube J, bored to receive the rods K K, so that the said
tube with the crank spindle, can slide to and fro in the box on the said rods. M M are
also projections on the tube J, drilled and tapped to receive a screw N, supported and
capable of rotation in hearings in the ends of the box. End motion of the screw is
prevented by a collar N¹ and nut N².
A light shaft P drives, through bevel gears QQ, a light shaft R, which is con-
nected by a universal joint S to the end of the screw N, so that when the hand-
wheel P on the end of the shaft P is rotated, the spindle H is moved along the
rods K, K.
The chain wheel consists of a disc T, keyed on the spindle H, and having radial
arms adapted to slide in radial slots therein. W is a disc provided with a hub or
sleeve W which can rotate upon the hub T¹ of the dise T. On the inner face of this
disc Wa scroll W2 is cut, and suitably shaped teeth VI on the arms V engage with
the said scroll, so that by its rotation the said arms V can be simultaneously and
equally extended or retracted, in the well-known manner; the action being similar to
that of a self centreing scroll chuck for a lathe.
The outer ends of the arms V are provided with arcs V2, on which are cut the chain
teeth V8.
In this instance instead of using a single coiled spring to automatically rotate the
scroll disc W, two coiled springs are employed, they are contained in the boxes X, X,
capable of rotation on arbors X', X', fixed in pieces X2, X2, attached to the rim of
the disc T. The inner end of each spring is coupled to its arbor X', while the outer
end is secured to the box. Each box is formed with, or fixed to a spur wheel X³,
gearing with spur teeth W³ on the sleeve W₁. If now the crank spindle H with the
disc T be rotated in the usual forward direction, while the disc W is by any means
prevented from rotating, the arms V will be drawn in as they are carried round the
scroll, while at the same time the springs in the boxes X, X, will be wound up. On
the release of the disc W, the said springs will unwind and in so doing rotate the
disc W within the disc T, thereby causing the arms V to be again extended.
The brake shewn for stopping the disc W is constructed as follows.
Y is a long block, mounted by links Z, Z', on pins a a fixed to the box C, so that
it can rise or fall a short distance. Its upper face is formed with ratchet teeth Y',
which, when it rises, engage with ratchet teeth Y2 on the sleeve W' and so hold the
scroll disc stationary. Facing the collar N' on the screw N is a loose sleeve N³, both
it and the collar N are provided with ratchet teeth b, and these teeth are normally
kept interlocked by a spring within the sleeve N³ (not shewn in the drawing). On
the outer face of the sleeve №3 are two cams or projections c c.
d is a lever fulcrummed at e, its lower end is connected by a link to an extension
of the lever link Z, and its upper end is provided with a roller g. A spring h
pulls it up against a stop on the box C. Now supposing the chain wheel to be at its
largest diameter, as shewn in Figs. 3 and 4, the spindle H will be at that end of the
box C nearest the driving wheel of the machine. If it is desired to gear the machine
down, the rider turns the hand-wheel P' in the direction to rotate the screw N to
move the spindle H forward. When the said screw is turning this way, the
sleeve N³ is driven by the ratchet teeth 6, and as each cam e passes the roller g, the
upper end of the lever d is pushed out and the block Y is raised, so that its ratchet
teeth Y¹ engage with the teeth Y2 and stop the rotation of the scroll disc. At each

page_text: such stoppage the arms V are drawn in a little by the rotation of the disc W, as-
before described, till by the time the spindle H arrives at the end of its traverse the
said arms are close in to the disc W and at their smallest diameter, as shewn in Fig. 1..
The cams care of such form that if the rider leaves one of them in contact with the
roller g it will not remain in such position, so that unintentional permanent locking
of the disc T is not possible. By stopping the movement of the spindle H on the
guides at any intermediate point, any desired ratio of gear between the two extremes..
may be obtained. To enlarge the chain wheel again, the hand wheel P¹ is rotated in
the opposite direction to move the spindle H back. The ratchet teeth b now slip.
past each other and as the chain slackens, the springs in the boxes X X become free
to unwind and rotate the scroll disc to extend the arms V and take up such slack..
These springs are of such strength and so adjusted in relation to the weight of
the chain, that the armis V are never extended sufficiently to make the chain too tight.
for free driving.
i is a casing within which is pivoted a discj driven by gearing, as shewn, from the
shaft P, and such gearing is so proportioned that the said disc makes nearly one
complete revolution for the entire traverse of the spindle H. Around the face of the
disc are marked various definite ratios of gearing, and when the two pins k, k on
the wheel P1, are in line fore and aft with one of these numbers, the rider knows that
that particular ratio of gear is in operation. A bell or other audible signal may be
combined with the disc for use at night.
In Figs. 6, 7 and 8, shewing one form of the chain I employ, each link is formed
of a pair of plates 1, 1, joined by rivets m m and having vertical slots n in which
rollers p are free to rotate and slide, so that any such roller coming in contact.
with the top instead of the side of a tooth V3 on the chain wheel will merely
be pushed up out of the way, and the teeth thus automatically pick out the particular
rollers which will engage correctly with them. Each plate i has an extension l' by
which it is hinged to the next plate by a rivet g.
The teeth on the chain wheel r, on the driving wheel hub, are of such depth
that they take the rollers p when they drop to what becomes the bottom of the slots,
as the under half of the chain travels towards the said wheel.
If the whole of the arms V were provided with teeth, there would be a tendancy
for them to lock in the chain when changing diameters, I therefore provide some of
them with blank arcs, which entirely overcomes this difficulty and still leaves an ample
number of teeth for driving purposes.
In Figs. 1 and 3 each alternate arm is left blank, but I do not confine myself to.
this particular proportion.
To define the extent of traverse of the radial arms V in the disc T, I provide two or
more radial slots in the said disc and insert pins in the back of the arms V to work
in such slots.
Suitable covers (not shewn in the drawings) are provided for the sides of the
box C, and the chain, chain wheels and brake mechanism are enclosed in a gear case
of any suitable form or construction. If desired the box C may be of such shape as
to contain the whole of the brake mechanism, while the shaft R and gears QQ may
be contained within the tube D.
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 :-
:-
1. In a cycle variable chain driving gear, the combination, in the pedal chain
wheel, of a scroll extension mechanism and a coiled spring for operating the said
scroll, substantially as described.
2. In a cycle variable chain driving gear, the combination in the pedal chain wheel
of a scroll extension mechanism and two or more coiled springs in boxes for
operating the said scroll through the medium of gearing, substantially as described.
3. In a cycle variable chain driving gear, the combination with the pedal spindle.

page_text: of means for its horizontal adjustment to take up the chain slack, substantially as
described.
4. In a cycle variable chain driving gear, a chain consisting of plates 1, 1, con-
nected by rivets m, m, and having slots n and rollers p, working in said slots, said
links being hinged together by rivets 9 in extensions, substantially as and for the
purpose herein set forth.
5. In a cycle variable chain driving gear, the combination with a chain formed as
in the preceding claim, of side bars or rollers with or without additional plates, and
a double toothed chain wheel on driving wheel hub, substantially as and for the
purpose herein set forth.
6. In a cycle variable chain driving gear, the combination of a scroll extension
pedal chain wheel, and a chain as set forth in Claim 4, substantially as described.
7. In a cycle variable chain driving gear, the combination of a scroll extension
pedal chain wheel, and a chain and driving wheel chain wheel, as set forth in Claim 5,
substantially as described.
8. In a cycle variable chain driving gear, the combination with the pedal spindle
bearings of horizontal guides to permit sliding motion to take up the chain slack,
substantially as described.
9. In a cycle variable chain driving gear, the combination with the pedal spindle
bearings of horizontal guides and a screw or screws to move said bearings in said
guides, substantially as described.
10. In a cycle variable chain driving gear, the combination with a screw or screws,
as set forth in the preceding claim, of means for operating the said screw or screws
by the rider, substantially as and for the purpose herein set forth.
11. In a cycle variable chain driving gear, the combination with a pedal chain
wheel scroll extension disc, of a brake for stopping the rotation of said disc,
substantially as and for the purpose herein set forth."
12. In a cycle variable chain driving gear, a brake for stopping the rotation of a
pedal chain wheel scroll extension disc, consisting of a ratchet toothed block Y inter-
mittently forced against ratchet teeth Y2 on the scroll disc sleeve W', by a cam action
from the pedal spindle traversing screw N, substantially as and for the purpose
herein set forth.
13. In a cycle variable chain driving gear, the combination of a shaft P, hand
wheel P¹, gears QQ, a shaft R, universal joint S, screw N, ratchet b, cams c, lever d
and brake block Y, substantially as and for the purposes herein set forth.
14. In a cycle variable chain driving gear, the combination, with the controlling
handle P, of a gear indicating device, substantially as described.
15. A cycle variable chain driving gear, consisting of the combination of a scroll
extension pedal chain wheel, a novel form of chain, screws and guides for horizontally
adjusting position of pedal spindle, a brake for stopping the motion of the scroll
extension disc, springs for automatically rotating said disc, and devices for operating
and controlling the said various mechanisms by the rider, substantially as described.
16. A cycle variable chain driving gear, constructed and operating substantially as
herein described and shewn with reference to the accompanying drawings.
Dated this 31st day of October 1896.
AMBROSE MYALL,
2 Lancaster Place, London, W.C., Agent for the Applicant.