Year: 1896

page_text: Date of Application (in United Kingdom), 28th Jan., 1896
Complete Specification Left, 28th Jan., 1896-Accepted, 28th Mar., 1896
COMPLETE SPECIFICATION.
I, STEPHANE DRZEWIECKI of 21 Boulevard Poissonnière, Paris, in the Republic
of France 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:-
My invention relates to improvements in the construction of bicycles and has
for its object to provide a bicycle in which the pedal cranks engage directly without
any intermediate mechanism by means of two internally toothed rings with the two
ends of the nave of the rear wheel.
This arrangement secures the following advantages:-
1. The ordinary chain gear which is a cause of considerable annoyance to
evelists is dispensed with and replaced by a gear of much greater efficiency in
work.
2. The rider while retaining a vertical position on the saddle can exert a
maximum effect on the pedals since his centre of gravity is vertically over the
pedals whereas in ordinary bicycles the rider is obliged to bend himself to an
objectionable extent in order to bring his centre of gravity in the best position for
doing work, i.e. directly over the pedals.
3. Dispensing with the pedal shaft in front of the rear wheel allows the frame of
the machine to be shortened, thereby obtaining a greater rigidity with less weight
and at the same time permitting of much shorter turns to be made with the
machine.
4. Since the weight of the rider bears almost entirely on the rear wheel,
overbalancing of the latter becomes impossible and the fork of the front wheel,
sustaining so little weight does not incur the usual liability to bend or break.
Moreover the present arrangement prevents the slipping or skidding of the rear
wheel on wet or smooth roads.
5. All the driving mechanism may be enclosed by a cap or cover to protect it
from mud or dust.
6. The wheel is driven from both sides so avoiding any straining or bending of
the frame caused by gear placed at one side of the machine only.
Figure 1 of the accompanying drawings shews in side elevation a bicycle
constructed according to this invention and Figure 2 is a horizontal section of the
same drawn to a larger scale. The nave C of the rear driving wheel turns on hall
bearings running on surfaces on the shaft A which is mounted securely at each end
by screws and nuts in rear brackets 13 formed on, or carried by, the frame of the
machine. Each end of the said nave C is provided with a pinion C¹ firmly secured

page_text: thereto or formed therewith. The brackets B form a part of lateral boxes D for
the pedal centres, the said boxes as shewn being formed with tubular junction
pieces in which are secured the ends of the tubes forming the frame of the
machine, the pedal boxes themselves thus forming a part of the frame being
connected together by the fixed shaft A.
Cups are mounted in these pedal boxes on which rotate on ball bearings conical
parts or collars formed on shafts E constituting the pedal centres which carry
internally toothed multiplying gear rings G. To effect this each shaft E is firmly
attached to a spoked wheel F depending in diameter on the increase of speed
desired to be obtained, to the interior of which the aforesaid toothed ring is fixed
or in which it is formed.
Or the spoked wheel F may be replaced by a solid wheel or cap which in this
case also forms a protector. Where the spoked wheels are employed a projecting
covering is used which may be formed of a thin metal sheet Filling the spaces
between the spokes of the said wheels. The toothed rings G secured within or
formed on the flange of the gear wheels Feugage with the pinions C and serve
to transmit to the driven wheel motion imparted to the treadles but at an increased
rate of speed.
By the fixed cap L having its edges bent so as to cover over the rim of the
wheel F, the transmission mechanism is completely enclosed and protected from
dust or mud as aforesaid. The wheels F or the like which carry the multiplying
gear rings G also carry the cranks H terminating in the pedals 1. The tubes of
the frame K supporting the saddle are set in a vertical plane and cause the weight
of the rider to bear more directly on the axis of the rear wheel. The forepart of
the machine is or may be similar to bicycles of ordinary construction.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I
claim is :-
what I
1. In bicycles the combination with the pedal cranks of two internally toothed
rings, one attached to each of the cranks and engaging respectively with pinions
keyed to the two ends of the nave of the rear wheel the said nave revolving on a
fixed shaft serving as a support to the two symmetrical portions of the frame
substantially as herein before described.
2. The construction arrangement and combination of parts constituting the
improved bicycle substantially as hereinbefore described and illustrated in the
accompanying drawings.
Dated this 28th day of January 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.