Improvements in Velocipedes.
Year: 1893

page_text: Date of Application, 23rd May, 1893
Complete Specification Left, 18th Oct., 1893-Accepted, 2nd Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in Velocipedes.
I, SAMUEL MCCORMACK, 4 Palmerston Road, Dublin, Ireland, Hosiery
Manufacturer, do hereby declare the nature of this invention to be as follows:-
My invention relates to an improved construction of frame for those velocipedes
which are provided with gear wheels and a chain such as is found for instance in
the ordinary rear driving safety bicycle.
According to my invention I construct the frame of suitable rods or tubes joined
together by brazing in the ordinary manner but said rods or tubes are of such
lengths that the bearing of the gear wheel axle or what is known as the bottom
bracket is some distance above the centre or near the top of the driving wheel.
By this construction the gearing and bearings of the gear wheel and also the
feet of the rider are kept clean even in muddy and wet weather which is
not the case with chain driven velocipedes of the ordinary construction; also
the liability of wheels to slip sideways due to the thrust on the crank when
the latter is in its lowest position is reduced because the crank axle is very
much further from the ground. Moreover by my improved construction of
frame the saddle and handle bars are brought closer together allowing the rider
to pull on the handle bars as he presses down with his foot on the pedals
thereby effecting a great saving and gain of power which is especially useful in
riding up hills.
The advantages of my improved construction are, the pull on the driving
chain tends to lift the driving wheel slightly which lifting is useful on soft
or loose roads. With bicycles constructed with my improved frame, the rider's
weight is more equally divided between the front and back wheels and his
attitude is more graceful than in the case of the rear driving bicycle of the usual
pattern.
Dated this 22nd dow of M-1002
SAMUEL M°CORMACK.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Velocipedes.
I, SAMUEL MCCORMACK, 4 Palmerston Road, Dublin, Ireland, Hosiery
Manufacturer, 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 velocipedes of the kind or class that are provided with
chain driving-gear such as is found for instance in the ordinary rear-driving safety-
bicycle, and it has for its object to provide an improved frame for such machines
whereby the bracket which carries the pedal crank axle is placed much higher
relatively to the driving wheel than has heretofore been the case.
According to my invention I construct the frame of suitable rods or tubes joined
together by brazing in the ordinary manner but said rods or tubes are of such
lengths and so arranged or combined that the bearing of the pedal-crank axle or
what is known as the bottom bracket is situated some distance above the centre, or
Pin1

page_text: nearly level with the top, of the driving-wheel. By this construction I gain
numerous advantages which I shall hereinafter indicate.
In order that my invention may be more readily understood I will proceed to
describe the same with reference to the accompanying drawing which shews a side
view of a rear-driving bicycle the frame of which is constructed in accordance with
my invention.
A is the front or steering-wheel; B is the driving-wheel; C is the driving chain
which passes round the chain-wheel D fixed on the pedal-crank axle and round the
pinion B¹ fixed to the driving-wheel. The pedal-crank axle D' rotates in suitable
bearings formed in the bottom bracket D'. The frame comprises six members E¹, E³,
E', E, E E' formed of rods or tubes which are connected together in the
usual manner at their intersections. The bottom bracket D2 is situated at the
intersections of the members E', E³, E³.
The important feature of my invention is that the lengths of the members of
the frame are so proportioned and so arranged that the whole of the chain-wheel D
is higher than the centre of the driving wheel.
I preferably arrange that the two bottom members E¹ and E' of the frame shall
be in the same straight line, as shewn in the drawing, which construction I find
forms a very rigid support for the bottom bracket. I may however lengthen or
shorten the diagonal member E³ or in other words increase or diminish the distance
between the crank axle and the ground so that the two members E' E' make an
angle with each other, but as before stated the bottom bracket which is placed at
the intersection of said members E', E' is maintained at a level which ensures the
chain-wheel being entirely above the level of the centre of the driving-wheel as
hereinabove stated. It will be moreover obvious that by the use of these straight
members E' and E' I obtain a more rigid carrier for the crank axle than by any
similar arrangement involving the formation of an angle for this purpose.
The remaining members of the frame are so proportioned that the saddle shall
be at a suitable distance from the crank axle and the handle bar a proper distance
from the saddle. These dimensions will vary according to the physical
characteristics of the rider.
Among the numerous advantages obtained by my construction of frame are the
following, the gearing and bearings of the chain-wheel and also the feet of the
rider being raised far above the ground are kept clean even in muddy and wet
weather, which is not the case with chain-driven velocipedes of the ordinary
construction; also in the case of bicycles the liability of the wheels to slip
sideways due to the thrust on the crank when the latter is in its lowest position is
very greatly minimised if not completely obviated by reason of the position of the
crank axle which is as before stated, higher than the centre of the driving wheel,
and therefore very much further from the ground than in ordinary safety bicycles.
To make this advantage which is a cardinal feature of my invention more clearly
understood, it will be sufficient to observe that any thrust on the crank even when
the latter is at its lowest position, will be distributed over the frame above a
horizontal line drawn through the centre of the driving wheel and consequently
will have less effect in causing side slip than when the thrust is near the ground.
Moreover by my improved construction of frame, the saddle and handle bars may
be brought closer together, allowing the rider to pull on the handle bars as he
presses down with his foot on the pedals, thereby effecting a great saving and gain
of power which is especially useful in riding up hills.
Other advantages of my improved machine are, the construction of the frame
tends to more equally divide the rider's weight between the front and back wheels,
and the extra rigidity and lightness of the frame contributes to an increase of speed
and ease in driving. The attitude of the rider is also more graceful than in the
case of the rear-driving bicycle of the usual pattern. A roadster machine
constructed according to my invention weighing say 33 lbs. will stand more rough
usage than the ordinary cycle weighing 45 lbs.

page_text: 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. A rear-driven bicycle having chain driving-gear, so constructed that the
chain-wheel D on the pedal-crank axle D' is entirely above the level of the centre
of the driving-wheel, and is carried by a rigid bottom member connecting the rear
driving wheel with the front fork.
2. In a bicycle such as is claimed in the first claim, having the bottom member
composed of two rods E' and E' in the same straight line, and having the bottom
bracket D situated at the junction of the rods E' and E³, substantially as
described.
3. A bicycle constructed substantially as described with reference to the
accompanying drawing, for the purposes specified.
Dated this 18th day of October 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.