Improvements in Velocipedes.
Year: 1893

page_text: Date of Application, 29th May, 1893
Complete Specification Left, 28th Feb., 1894-Accepted, 14th Apr., 1894
Improvements in Velocipedes.
I, WILLIAM BORTHWICK SMITH, of 139, Cannon Street, in the City of London,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to bicycles, tricycles, and other velocipedes, and more
especially to what are known as geared ordinary" bicycles, in which the
revolution of the axle driven by the pedals worked by the rider, communicates a
quicker revolution to the driving wheel of the machine.
The improved apparatus for this purpose consists of an internally toothed wheel
fixed upon the pedal axle, and a smaller externally toothed wheel, having the same
pitch of teeth, concentric with the first and formed or fixed upon a sleeve or tubular
axis which carries the driving wheel and turns freely upon the inner axis.
In the space between the teeth of the two toothed wheels described 1 arrange an
endless chain, the inner side of the links of which fit over the teeth of the inner
wheel, and their outer side over a sufficient number of the internal teeth of the
outer wheel. In order to keep the chain properly in gear with the teeth of the
latter wheel, I arrange a curved plate or guide projecting from or carried by
the fork of the bicycle or other fixed support, between the teeth of the two wheels
and inside the chain. This guide is so arranged that the links of the chain pass
over its outer side and are kept properly in gear with a sufficient number of the
internal teeth. The ends of the pins which connect the links of the chain
preferably project sufficiently to receive friction rollers which rest and run upon
the guide described, which is made of sufficient width.
Ball-bearings or other anti-friction bearings, are preferably arranged in the usual
way in the different bearings of the apparatus, and the curved guide described may
be made adjustable for a short distance in order to tighten the chain when
necessary.
The apparatus described is very simple, light, and effective, and occupies very
little room. By substituting wheels of different diameters, varying relative speed>
may be obtained.
In a somewhat modified form, I use concentric wheels having internal and
external teeth respectively arranged in a similar way to those just described, but
instead of a chain I use a wheel or disc arranged by the side of the others and close
to them. The imaginary centre of this disc is situated between the pitch line of the
internal teeth of the larger wheel and the pitch line of the external teeth of the
smaller wheel upon the opposite diameter, and the disc has teeth or pins at its side
gearing with both the internal and external teeth.
The disc has a central opening of sufficient diameter to allow the central bearings
of the wheels to pass through it, and it turns (with the intervention preferably of
anti-friction balls) in a fixed bearing carried by the fork or frame of the machine.
The pins may be provided with friction rollers."
By the use of the novel apparatus described, it is evident that when the pedal
shaft is made to rotate, the concentric wheel hub or axis is made to rotate in the
same direction but at a greater speed, the relative velocities being dependent upon
the sizes of the externally and internally toothed wheels.
In the device first described, an arrangement may be used by which the curved
guide can be removed, and the chain locked to the toothed wheel or wheels, so that
the speed of the driving wheel is the same as that of the pedal axle. In the device
last described the same result may be obtained by moving the pin wheel or disc

page_text: end ways so that it is freed from the bearings upon which it turns and is locked to
both toothed wheels. Or other equivalent methods may be used.
I do not confine myself to the precise form, proportions, and method of arrange-
ment, of the different parts which may be varied more or less as may be found
advisable.
1
001
1902
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.
Improvements in Velocipedes.
I, WILLIAM BORTHWICK SMITH, of 139, Cannon Street, in the City of London,
Engineer, 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 and accompanying drawings, that is to say :-
This invention relates to bicycles, tricycles, and other velocipedes, and more
especially to what are known as "geared ordinary" bicycles, in which the
revolution of the axle driven by the pedals worked by the rider, communicates a
quicker revolution to the driving wheel of the machine.
It has for its object novel methods of obtaining the desired result.
The improved apparatus for this purpose is illustrated in the accompanying
drawings, Figure 1 being a longitudinal vertical section, and Figure 2 a transverse
vertical section. It consists of an internally toothed wheel a fixed upon the pedal
axle b, which carries the pedal lever m, and a smaller externally toothed wheel c
having the same pitch of teeth as a and concentric with the latter, and formed or
fixed upon a sleeve or tubular axis d which carries the driving wheel and turns
freely upon the inner axis b.
In the space between the teeth of the two toothed wheels a and c described !
arrange an endless chain e, the inner side of the links of which fit over the teeth
of the inner wheel c, and their outer side over a sufficient number of the internal
teeth of the outer wheel a as shewn. In order to keep the chain e properly in gear
with the teeth of the latter wheel a, I arrange a curved plate or guide f projecting
from or carried by the fork g of the bicycle or other fixed support, between the
teeth of the two wheels a and c and inside the chain e. This guide is so arranged
that the links of the chain e pass over its outer side and are kept properly in gear
with a sufficient number of the internal teeth of the wheel a.
The ends of the pins which connect the links of the chain preferably project
sufficiently to receive friction rollers which rest and run upon the guide f
described, which is made of sufficient width.
Ball bearings or other anti-friction bearings, are preferably arranged in any of
the usual well-known ways in the different bearings of the apparatus, and the
curved guidef described may be made adjustable for a short distance in order to
tighten the chain when necessary.
The apparatus described is very simple, light, and effective, and occupies very
little room.
By substituting wheels of different diameters, varying relative speeds
be obtained.
ma
It is evident that if the chain e (Figure 1) is arranged so that the path which
the links take in passing round the wheel c and over the guide f is circular, it is
unnecessary that the links should be jointed but they may take the form of rigid
rings, as shewn in Figure 3. In this case the guide is circular.
It may, if
desired, be carried completely round the pinion (as shewn in dotted lines) the
central part being cut away to allow the teeth to pass through it, and the rollers /
running upon its edges. The rollers below the pinion may be supported upon
external guides, as shewn in dotted lines at f' in Figures 1 and 3.

page_text: Figure 4 shews in section a somewhat modified form of the arrangement shewn
in Figure 3. In this case I use concentric wheels a and c having internal and
external teeth respectively arranged in a similar way to those just described, but
instead of a chain or rings I use a hollow disc or ring arranged by the side of the
wheels and close to them. The imaginary centre of this disc or ring i is situated
between the pitch line of the internal teeth of the larger wheel a and the pitch line
of the external teeth of the smaller wheel c upon the opposite diameter, and the
ring has teeth or pins k at its side gearing with both the internal and external
teeth.
The disc or ring i has a central opening of sufficient diameter to allow the central
bearings of the wheels to pass through it, and it turns (with the intervention
preferably of anti-friction balls as shewn) in a fixed bearing carried by the fork
or frame of the machine. The pins k may be provided with anti-friction rollers or
bushes.
By the use of the novel apparatus described, it is evident that when the pedal
shaft is made to rotate, the concentric wheel hub or axis is made to rotate in the
same direction but at a greater speed, the relative velocities being dependent upon
the sizes of the externally and internally toothed wheels.
In the device first described, an arrangement may be used by which the curved
guide is made separate so that it can be entirely removed, and the chain locked to
the toothed wheel or wheels by a bolt or pin so that neither wheel can revolve
independently, and the speed of the driving wheel of the machine is then the same
as that of the pedal axle.
Or, as illustrated in Figures 5 and 6, the separate curved guide may be
attached to the fork g, by a screw a passing through a lug o upon the guide for
equivalent means as shewn in Figure 5, or to the inner side of the interna! toothed
wheel a, as shewn in Figure 6, as may be desired.
Or other equivalent methods may be used.
Or, as shewn in dotted lines in Figure 2, the axle may be locked to the pinion
by a moveable key or pin the wheel a being at the same time released so that it
turns freely without being connected to the pedal lever.
The main wheel of the machine will then revolve at the same peel as the pedal
axle.
If, on the other hand (as shewn in the figure), the wheel a be locked or
connected to the pedal lever, and the pinion c released from the axle, the improve!
gear will come into operation, and the main wheel of the machine will revolve at a
greater speed than the pedal axle.
I do not confine myself to the precise form, proportions, and method of arrange-
ment of the different parts, which may be varied more or less as may be found
advisable.
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 the toothed wheel a having internal teeth, the concentric
toothed pinion c having external teeth, the chain e gearing with both the wheel a
and the pinion c, and the fixed guide by which the chain e is maintained in its
proper position substantially as described and illustrated in Figures 1 and 2 of the
accompanying drawings.
2. In the combination described and claimed in Claim 1, the substitution of
circular rings provided with transverse pins gearing both with the wheel a and
the pinion c, substantially as described and illustrated in Figure 3 of the
accompanying drawings.
3. In the combination described and claimed in Claim 2, the substitution for the
circular rings provided with transverse pins, of the ring revolving in a bearing
carried by the frame of the machine, and provided with lateral pins k gearing
both with the wheel a and the pinion c, the fixed guide being omitted,

page_text: substantially as described and illustrated in Figure 4 of the accompanying
drawings.
4. The combination with the apparatus described and claimed, of means for
operating the main driving wheel of the machine either direct from the pedal axle,
or at an increased speed by means of the gear described and illustrated,
substantially as described.
Dated thie 28th day of Kohwavy 1001
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.