Improvements in or relating to Velocipedes or the like.
Year: 1891

page_text: Date of Application, 16th Mar., 1891-Accepted, 11th July, 1891
COMPLETE SPECIFICATION.
Improvements in or relating to Velocipedes or the like.
A communication from JULIUS ZIEGER, of Radeberg, Saxony, in the German
Bri
1:
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E.. 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:-
This invention relates to improved operating mechanism for driving wheels in
which two toothed wheels mounted upon the axle of the driving wheel or upon
the shaft of a special chain wheel (which shaft is connected with the said wheel-
axle on one side by means of a catch device) are in gear either with racks
movable in a straight line or with toothed segments swinging upon a stationary
pivot or pivots. These racks or segments as the case may be are alternately
depressed by the feet of the rider so that through the medium of the gearing
the axle of the driving wheel or the shaft of the said chain wheel (if any) are
set in continuous rotary motion. The return movement of the racks or toothed
segments which may be loose upon their shafts may be provided for either by
connecting both together in such a manner that the descending one raises the other
or by means of springs which will of their own accord draw back each rack
independently to its initial position.
A
The object of this new driving mechanism is to remely the defects which have
hitherto been noticeable in connection with the usual crank arrangement.
crank as is well known at a certain moment comes to what is termed the dead
centre. The consequence is that the operation of the mechanism and the motion
of the vehicle want uniformity or continuity as the foot of the rider acts upon a
lever which is short at first then lengthens, then becomes short again and lastly
dwindles down to zero. In the apparatus constructed according to this invention
the foot during the whole stroke acts upon a lever arm of an equal or practically
equal length throughout the time occupied by each stroke. The power expended
by the driver is thus put to better advantage and the driving-wheel may be moved
evenly and with ease however slow the pace.
Some of the forms of the improved arrangement are illustrated in the accom-
panying drawings in which Figs. 1 to 3 show the mechanism provided with racks
arranged for rectilinear motion.
next to the
As the gear
engage with the
Fig. 1 shows a safety bicycle provided with the improved operating mechanism.
Fig. 2 is a front view of the mechanism with the driving wheel frame in section.
Fig. 3 is a cross section illustrating the position of the racks in their guides.
A A are the racks sliding in guides a a permanently fixed to the frame and
carrying treadles aa. These racks gear with the toothed wheels B B loosely
arranged upon the shaft of the chain wheel C. Upon the shaft
toothed wheels B B are rigidly secured the ratchet wheels bb.
wheels B B are moved in one direction say forward the pawls
ratchet wheels under spring pressure. When however the wheels B B are turned
in the reverse direction say backwards the said pawls slide over the ratchet
wheels without catching. The chain wheel C transmits the motion it receives
by means of a pitch chain and suitable gearing to the axle of the driving wheel.
The return notion of the racks is effected by a chain d connecting both racks
together and passing over a suitable pulley d provided on the frame.
When one of the cranks is caused to descend by the depression of the treadle
the pawl of the corresponding toothed wheel engages with its ratchet wheel and
shaft is rotated while the other rack subjected to no weight or pressure for the

page_text: time being is raised by the chain & so that the pawl of the corresponding gear
wheel slips without catching over its ratchet wheel. In this manner by the
alternate depression of each rack the shaft is maintained in continuous rotary
motion.
A modification of the driving mechanism is shown in Figs. 4 to 6 being also
applied to a bicycle. In this instance toothed segments directly operate on the
axle of the driving wheel without the assistance of a chain.
Fig. 4 is an elevation of a bicycle with the driving wheel provided with such
operating mechanism and Figs. 5 and 6 are detail views.
The toothed segments E swing on a pivot or spindle e secured to the frame and
carry the treadles .
They are in gear with the toothed wheels FF loosely
mounted on the axle g of the driving wheel and adapted to transmit the motion by
means of pawls to the ratchet wheels frigidly secured upon the axle g
The return motion of the segments E is produced by springs pressing upwardly
upon the said segments. The operation of this form of mechanism is substantially
the same as that of the first mentioned form.
A third modification is represented in Fig. 7. In this case also toothed segments
are used but they do not act directly upon the axle of the driving wheel, but
through a chain gearing. The segments are here provided with inwardly projecting
teeth the rest being substantially similar to the arrangements hereinbefore
described.
Other modifications may obviously be carried out without departing from the
principle of this invention. The driving or operating arrangement described will
apply to driving or steering wheels of all descriptions.
Having now particularly described and ascertained the nature of the said
invention as comminunicated to me by my foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is :-
1. Wheel driving mechanism in which two toothed wheels mounted either upon
the axle of the driving wheel or upon the shaft of a chain wheel in gear therewith
and engaging with such shaft or axle by means of ratchet mechanism to gear either
with racks movable in a rectilinear direction or with toothed segments swinging on
a rigid or stationary spindle or pivot whereby owing to the alternate downward
pressure produced by the feet of the rider the driving wheel axle y or the chain
wheel shaft e as the case may be are set in continudus motion; the return movement
of the racks or of the toothed segments being either produced by the action of the
descending rack or segment or by springs substantially as described and illustrated
in the accompanying drawings.
2. The combination and arrangement of parts constituting the complete bicycle
substantially as described and illustrated in Figure 1 of the accompanying drawings.
3. The combination and arrangement of parts constituting the complete bicycle
substantially as described and illustrated in Figure 4 of the accompanying drawings.
4. The combination and arrangements of parts constituting the complete bicycle
substantially as described and illustrated in Figure 7 of the accompanying drawings.
Dated this 16th day of March 1891,
W. P. THOMPSON & BOULT,
Agents for the Applicant.