Year: 1897

page_text: I, ADOLF ROSENZWEIG, off Schwertgasse No. 2, Vienna, Austria, Manufacturer, do
ereby declare the nature of this invention to be as follows:-
All bicycles of known construction suffer more or less from the following defects :-
1. Only a comparatively small part of the power exerted upon the cranks is use-
fully employed, as at most one half of the crank circle is utilised, and of this only
half transmits the full power. In consequence hereof there are two dead centres in
the motion of the bicycle.
2. The front wheel is loaded to a considerable extent in consequence of the
arrangement of the saddle between the wheels, which causes loss of power when
running uphill, and this loss is increased in the case of machines with the cranks
directly on the front wheel on account of the disadvantageous positions of the feet
when the wheel is turned out of the central plane for steering.
3. The machines are not sufficiently stable because, with directly driven front
wheel the weight of the rider is almost entirely taken by this, and there is danger of
his being thrown forward over the handle bar, while with machines in which the rear
wheel is driven there arises the danger of lateral skidding or tipping over, caused on
the one hand by the axle of the driven wheel not being under the direct control of
the rider, and on the other hand the rider mostly becomes too late conscious of the
tipping motion to enable him to counteract it effectually by the bending over of his
body.
4. The machines cannot turn in sufficiently small circles, this being caused in the
case of directly driven front wheels, by the fact that by the turning of this wheel into
a considerable angular position the feet of the rider would be very inconveniently
placed, while with machines of which the rear wheel is driven, the necessary length
of the frame prevents the wheels from being brought into the relative positions for
going round very sharp curves.
By the present invention all these disadvantages are obviated. According to my
invention, the cranks are fixed on the axle of the rear wheel, and the saddle is so
arranged that the middle of the seat is exactly over the centre of the crank axle, or
very nearly so.
The rear wheel is not fixed on the crank axle, but runs thereon with a tubular hub
with ball bearings and the rotation of the crank axle is transmitted to the hub of the
wheel through suitable speed increasing gearing, such as a spur wheel fixed on the
crank axle gearing with a pinion running loose on a pin projecting from the framing,
which pinion is combined with a spur wheel that gears with a toothed ring on the
hub of the wheel; preferably I construct these wheels with pins carrying rotatable
discs instead of ordinary teeth, so as to reduce friction.
The crank axle is carried in ball bearings on the frame.
By placing the centre of the saddle directly over the axle of the rear wheel the
advantages are gained, firstly, that the load on the front wheel is reduced to a
minimum, whereby running up hill is facilitated, secondly, that about ths. of the
crank circle is rendered available for propulsion, and that the machine has no dead
centre of motion.

page_text: Moreover, the propelling force exerted by the rider is much more favourably
utilised owing to the position of his legs relatively to the cranks, and as he has
perfect command of the rear wheel axle, he can effectually counteract lateral tipping-
over, or skidding.
By the above described construction also, the length of the frame can be reduced
by about one third as compared with existing machines, and the machine can there-
fore be run round much sharper curves; the frame in addition to being of less weight
is stronger, and the frictional resistance of the running gear is much less than in
ordinary machines, where the rear wheel runs on a fixed axle as for one revolution of
the rear wheel, the motion of its hub relatively to its axle is greatly reduced because
the axle is also rotating in the same direction.
Dated this 20th day of October 1807
ABEL & IMRAY,
Agents for the Applicant."
"
Improved Construction of Bicycles.
I, ADOLF ROSENZWEIG, of I Schwertgasse No. 2, Vienna, Austria, 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:-
All bicycles of known construction' suffer more or less from the following
defects.
1. Only a comparatively small part of the power exerted upon the cranks is use-
fully employed, as at most one half of the crank circle is utilised, and of this only
half transmits the full power. In consequence hereof, there are two dead centres in
the motion of the bicycle.
.
2. The front wheel is loaded to a considerable extent in consequence of the
arrangement of the saddle between the wheels, which causes loss of power when
running uphill, and this loss is increased in the case of machines with the cranks
directly on the front wheel on account of the disadvantageous positions of the feet.
when the wheel is turned out of the central plane for steering.
By arranging the axle of the rear wheel as pedal crank axle, according to my
present invention, no part of the power exerted on the cranks is transmitted to the
front wheel, as is the case with all other constructions, and consequently any
additional friction in the front wheel bearing caused by the transmission of a
portion of the pressure thereto is avoided.
3. The machines are not sufficiently stable because, with directly driven front
wheel, the weight of the rider is almost entirely taken by this, and there is danger
of his being thrown forward over the handle bar, while with machines in which the
rear wheel is driven there arises the danger of lateral skidding or tipping over,
.caused on the one hand by the axle of the driven wheel not being under the direct
control of the rider, and on the other hand the rider mostly becomes too late conscious
of the tipping motion to enable him to counteract it effectually by the bending over
of his body.
4. The machines cannot turn in sufficiently small circles, this being caused in the
case of directly driven front wheels, by the fact that by the turning of this wheel
into a considerable angular position the feet of the rider would be very inconveniently
placed, while with machines of which the rear wheel is driven, the necessary length

page_text: .
of the frame prevents the wheels from being brought into the relative positions for
going round very sharp curves.
By the present invention all these disadvantages are obviated. According to
my invention, the cranks are fixed on the axle of the rear wheel, and the saddle is
so arranged that the middle of the seat is either exactly over the centre of the crank
axle, or very nearly so.
I will describe the construction of my improved bicycle with reference to the
accompanying drawing, in which Fig. 1 shews a side view of the machine, Fig..2 an
enlarged part cross section thereof taken through the hub of the rear wheels;
Figs. 3 and 4 shew diagrams.of.the crank action.
As shewn at Fig. 1, the axle a of the rear wheel b is made to constitute the.crank
axle, having the cranks e and d fixed thereon.
:.
The rear wheel runs with a tubular hub e upon the crank axle, and the rotation of
the latter is transmitted to the hub e through suitable speed increasing toothed
gearing f, g, h, i, these being preferably made with teeth consisting of pins on which
rollers are mounted in order to reduce friction, the wheel serving to transmit the
motion to a double wheel g h, running on a pin on the frame, and the wheel h being
geared with a toothed ring i on the hub e.
All the running parts are mounted on ball bearings as usual.
The saddle is not, as heretofore, placed at a considerable distance behind the
crank axle, but, as shewn on the drawing, it is placed exactly or almost exactly over
the crank axle, or over the highest point of the periphery of the rear wheel, and it is
consequently in such a position on the framing that only a minimum portion of the
load is transferred to the front wheel.
By the said arrangement of the saddle, about of the crank circle is effectively
available for propulsion, because, as Fig. 3 shews, the crank, after having been forced
down through half a revolution to the point in the vertical centre line, can be still
effectively propelled by the foot backwards through the arc 1 m, being about of the
circle, and which is not available with the ordinary position of the saddle relatively
to the crank-shaft. By this means also, the coincidence of the two dead centres of
the two cranks is prevented, and consequently there is no dead point in the motion
of the machine.
Furthermore, a greater amount of power is developed during the half circle nl of
of the cranks motion than is possible with ordinary bicycles, because on the one hand
the dead weight of the leg operates more effectively, and on the other hand, the
muscles of the leg exercise their power more naturally in moving straight downwards
and slightly backwards; in addition, the leverage at which the muscular power has
to act, and which with the ordinary arrangements is equal to the length o of the
thigh, Fig. 4, when acting on the raised pedal, is greatly reduced with the present
arrangement as at Fig. 3, where the fulcrum of the lever represented by the thigh is
brought in the vertical centre line of the crank axle, enabling the power of the thigh
and hip muscles to be exercised much more advantageously.
With the improved construction also, the load on the front wheel is reduced to a
minimum, the steering and driving are exercised on different wheels and the axle of
the driving wheel is directly controlled by the feet of the rider, whereby he is enabled
to effectually counteract any lateral tipping over or side skidding; also, the steering
fork being arranged at a less incline, the steering is more easily and accurately
effected.
With the above described improved construction the framing can be made about
one third shorter than in ordinary machines, whereby the running round sharp curves
is greatly facilitated, and the framing, notwithstanding that it is lighter, is consider-
ably stronger than in present machines.
Lastly, the frictional resistance of the rear wheel is, with a gearing-up of 1 to 3
decreased by about one third, as while the rear wheel is revolving three times, the
axle on which it runs revolves once in the same direction, so that the hub of the
wheel only revolves twice round the axle during that time.
Having now particularly described and ascertained the nature of this inven
"

page_text: tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A bicycle wherein the rear wheel axle constitutes the crank axle on which the
hub of the wheel rotates, the motion of the axle being transmitted to the hub of
the wheel through toothed wheel transmission, such as f, g, h, i substantially as
described.
2. In a bicycle such as is referred to in the first claim wherein the rear wheel axle
constitutes the crank axle, arranging the saddle k more or less vertically over the
crank axle a, substantially as and for the purposes described.
1
ABEL & IMRAY,
Agents for the Applicant.