Improvements in Differential Gearing, applicable to Driving Velocipedes and for other Mechanical Purposes.
Year: 1892

page_text: Date of Application, 26th Oct., 1892
Complete Specification Left, 16th Dec., 1892-Accepted, 29th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Differential Gearing, applicable to Driving
Velocipedes and for other Mechanical Purposes.
JOHN FLETCHER WILES 128 High Street Croydon Surrey Insurance Broker
do hereby declare the nature of this invention to be as follows:-
The object of this invention is to obtain a differential speed between the
driving shaft and the driven wheels shafts or other portions of velocipedes or other
mechanism.
For this purpose I construct a train of gearing wheels composed of three or
more bevel cog wheels gearing into each other at right angles to each other and
preferably all of equal diameters.
In applying it to velocipedes, at or about the centre of the shaft which is
driven by the cranks and pedals is rigidly fixed a spindle at right angles thereto
carrying one or more bevel cog wheels at either or both ends, the said shaft running
through the centre of the hub of the driving wheel of the velocipede.
The above bevel cog wheel or wheels gear into two bevel cog wheels at right
angles and running on ball or other bearings on the main shaft, one being upon each
side of the centre spindle.
One of the bevel cog wheels is held in a bearing or friction clutch fastened to the
end of the fork on one side of the machine and the other bevel cog wheel is securely
fastened to the interior or end of the hub of the driven wheel.
When the bearing or friction clutch is tightened by a fly nut or other convenient
device sufficiently to prevent the bevel cog wheel revolving, the driven wheel will
revolve twice the number of revolutions of the mainshaft but when the friction
bearing a clutch is released sufficiently to allow the bevel cog wheel to revolve, the
driven wheel will revolve only the same number of revolutions as the mainshaft,
thus making a changing gear at the will of the rider by simply loosening or
tightening the friction bearing or clutch by means of the fly nut or other convenient
device placed within convenient reach of the rider, enabling him at any time to
alter the gear of the machine without dismounting.
This device may be applied to any purpose requiring differential
and
changin
COMPLETE SPECIFICATION.
Improvements in Differential Gearing, applicable to Driving
Velocipedes and for other Mechanical Purposes.
I, JOHN FLETCHER WILES, of 128 High Street, Croydon, in the County of
Surrey, Insurance Broker, 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 :-
"
My invention relates to improvements in differential gearing, and consists in
a train of gearing combined with a device by which it can be converted into an
epicyclic train at will. These improvements are applicable to the driving gear of
velocipedes, as well as to any mechanism in which it may be necessary or desirable
that the relative speeds of two axes should be variable in a gradually increasing
ratio according to the will of the user, without his being limited in respect of the.
intermediate ratios by the construction of the gearing.

page_text: In order that the invention and the best means of carrying it into practical effect,
may be thoroughly understood, I will now describe it and them in detail, referring
in so doing to the accompanying figures which are to be taken as part of this
Specification and read therewith. They illustrate the application of the invention
to a bicycle and I have selected this application for illustration and specification
because it is one for which the invention is peculiarly adapted, but it is to be dis-
tinctly understood that the latter is not confined to this application.
Fig. 1 is a side elevation of a bicycle.
Fig. 2 is a front elevation corresponding therewith.
Fig. 3 is a sectional elevation through the hub of the driving wheel of the
bicycle.
Fig. 4 is a sectional side elevation of the hub from the off side.
a is the crank axle; and b, the hub of the driving wheel. The former stands for
the driver and the latter for the driven member of any mechanism to which the
invention is applicable. The terms "axle" and "hub' are used hereinafter to
convey this relationship, the former standing for "driver" and the latter for
"driven member."
c, c' are the limbs of the fork. One of them-the near one in the figures-is of
any suitable section and is attached to the axle in the usual way. The opposite one
is modified to meet the requirement of my invention, in the manner illustrated and
described further on.
d, dare a pair of stud axles projecting at right angles from the axle a.
stand, preferably, opposite each other with their axes in the same plane.
They
e is a mitre wheel loose upon the stud axle d, and f is a second mitre wheel loose
upon the opposite stud axle d'. They are duplicates of each other and either may be
dispensed with. I prefer to use both for the purpose of driving the wheel next
described from two opposite points.
is a mitre wheel loose upon the axle a but made fast to the hub in any
convenient way. In the case of a velocipede prefer to connect the two in the
manner illustrated, viz., by means of a disc g', flange g² and screws g³.
h is a fourth wheel. It is loose upon the axle a on the opposite side of the
wheels e, f, to that on which the wheel g is mounted.
The four wheels e, f, g, h are always in gear with each other and, therefore, form
an epicyclic train. The two former are held in their respective positions by any
convenient device, e.g., nuts, e¹, which are screwed on and pinned to the
respective stud axles d, d. The wheel g is held up in gear by the cone of the
adjacent hub bearing go, and the wheel h, by that of the adjacent hub bearing 2.
The latter is made fast to the hub in the same way as the wheel g is. The
bearing of the fork c' is formed in the outer end of the prolongation i next
described.
.
The special means by which the relative speeds of the crank axle and the hub
are differentiated consists of any suitable type of friction clutch adapted to act
upon the wheel h. The one illustrated consists of the following devices. i is a
prolongation of the boss of the wheel h. It is, like the latter, loose upon the
axle a and is continued outside the hub far enough to receive the leg c¹ of the fork.
The lower portion of this is solid for some distance and terminates in a ring c² in
which latter are fitted a pair of clutches k, . Each clutch consists of, preferably,
a semi-circle rectangular in cross section and having a V-shaped ridge standing,
out centrally from its inner surface and running parallel with the side of the
clutch.
the two Al V-shaped groove is cut in the periphery of the prolongation i to receive
may use more than one ridge on each clutch, grooving the
prolongation accordingly. The ends of each clutch stop short of the horizontal
centre line far enough to allow of the clutches being moved towards the axis of the
prolongation as far as suffices to hold it, and with it the mitre wheel h, stationary
with reference to the mitre wheels e or f. When the wheel is so stationary, it
becomes the first or dead wheel of the epicyclic train. The solid portion ca
already referred to is bored and threaded internally to make it serve as the fixed

page_text: nut for a screw j. The rod of it is continued upwards through the leg where it
receives a hand wheel by which the screw can be moved towards or away from
the prolongation i. I do not confine myself to the use of the screw ; and the
nut for the purpose of actuating the clutches but may make use of any other
mechanism adapted to produce the same effect.
My invention acts in the following way. If the screw be screwed down, the
clutch is forced downwards and that ki pulled up. This locks the prolongation i
and holds the wheel stationary. The rotation of the axle a will necessarily drive
the wheel g, and with it the hub b, at twice its own speed. If the clutches be
taken off the prolongation, the axle a will rotate the wheel g at its own speed.
These are the two extreme conditions. There are any number intermediate
between them according to the degree of grip which the clutches k, k¹ exert upon
the prolongation i. The nearer the wheel h is to being stationary, the greater will
be the length of ground over which is spread the expenditure of the rider's
energy in depressing a crank once.
It must be explained that there is in my invention a capacity for automatically
adjusting itself to the changed conditions of the road. For instance, supposing
the rider is riding along the level with the clutch on and comes to a hill, he will,
as he feels the latter, begin to tread harder, with the result that the grip of the
clutch is loosened to some extent, and the driver's energy concentrated upon the
axle accordingly.
In the drawings, the clutch and its actuating device are shewn as on the off side
of the machine. Whether they are on the near side or the off side is a matter of
convenience to the rider. The relative position of the members of the train of
gearing is decided accordingly.
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 combination of driver or axle, an epicyclic train of gearing, a driven
member or hub fast to the last wheel of the train and co-axial with it and a
device by which the first wheel of the train can be held dead or stationary, as set
forth.
2. The combination with the crank axle of a velocipede, of an epicyclic train
adapted to rotate about the said axle, a device by which the rider can from his
seat render the first wheel of the said train dead or stationary and means by which
the last wheel of the same train is always held fast to the hub and concentric
therewith, as set forth.
3. The combination of hollow leg of fork, screw adapted to be rotated about its
axis within a nut fixed at the end of the said leg, a clutch held within or to the
said end and a gear wheel adapted by being clutched to the said leg to serve as
the dead wheel of an epicyclic train, as set forth.
Dated this 14th dox of December 1802
PHILLIPS & LEIGH,
22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.