Improvements in or relating to Variable Speed Driving Gear of Bicycles and other Vehicles.
Year: 1896

page_text: Date of Application, 14th Aug., 1896-Accepted, 5th Dec., 1896
COMPLETE SPECIFICATION.
Improvements in or relating to Variable Speed Driving Gear of
Bicycles and other Vehicles.
I, OSCAR LUTHER of 76^ Gabelsberger Strasse, Munich in the Empire of Germany,
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 :-
The object of this invention is to enable the cyclist whilst riding to change the
gear from a low one to a higher one or from a high one to a lower one, according to
which gear is more suitable for the portion of the road to be passed. The device is
of such nature as to be easy of manufacture and therefore cheap, light and not easily
damaged by dirt and dust and will not detract from the elegant appearance of the
machine.
Fig. 5 shows the manner in which two dissimilar gears may be fitted to a bicycle.
The two chain wheels 1 and 2 of equal diameter are loose on the hub of the rear-
wheel and are respectively driven by means of chains or the like by two wheels 3
and of unequal diameters keyed on to the crank shaft of the machine.
When one of the two loose wheels 1 and 2 is coupled to the rear-wheel of the
bicycle one of the gears becomes operative. This coupling is effected by reason of
the device hereinafter described.
In Fig. 1, 5 represents the wheel axle screwed into the cycle frame 6, the hub 7
with the spokes 8 being capable of rotating round said axle. 1 and 2 are the above-
mentioned loose wheels on the hub 7 having holes 9 parallel to the axle, opposite
which are exactly similar holes 10 in the hub at the same distance from the axis.
In these holes 10 are supported one or several movable coupling pins 11 which when
in their central position do not touch either of the chain wheels 1 and 2, but when
pressed to the right or left hand side, they engage with the holes 9 as the wheel
revolves and thus the chain wheel 1 or 2 will be coupled to the cycle wheel. The
coupling being thus obtained it is now necessary to make a suitable connection to
be operated by the cyclist so as to enable him whilst riding to bring either gear into
action.
To this end a coupling device is used which forms the principal object of the
present invention.
The part from which the coupling receives its movement is a longitudinally
adjustable sleeve 12 around the hub 7 which sleeve is secured to the coupling pin
or pins 11 by means of arms 13, the pins or projections 14 of said sleeve entering
the inner bollow space of the hub 7 through a longitudinal slot 15 in the hub.
Another sleeve 16 arranged in the hub but not taking part in its rotation engages
by means of a groove 17 with said pins and causes them to take part in each of its
axial movements, the groove allowing at the same time free rotation of the pins
together with the sleeve and hub.
This ring 16 receives its movement by means of a pin 18 arranged in the hollow
axle 5, which pin is connected to the ring 16 by a cross pin 19, axial slots 20 in
the wall of the axle affording means for the passage and longitudinal play of the
said pin 19.
Any longitudinal movement of the pin 18 is thus transmitted to
the ring 16 and from the latter to the sleeve 12 and thus to the coupling pins 11.
In order to effect the transmission of movement between the pin 18 and the
hand of the cyclist in a simple manner, there is arranged behind the pin 18 a

page_text: spring 21 which normally holds one of the chain wheels coupled to the road wheel.
A simple bell crank lever 23 pivotted on a pin 22 and having a cord 24 guided
over pulleys 25 and 26 (Fig. 5) and connected to the hand-lever 27, is sufficient
to transmit the movement. As long as the hand-lever 27 is pulled to stretch the
string in the direction of the arrow, one of the chain wheels is coupled. If the
hand-lever is released, the other wheel becomes operative.
For carrying out the invention it is of course immaterial whether the driving
wheels are sprocket or toothed wheels or rope or belt pulleys, whether one or
several pins 11 effects the coupling, whether one ring 16 with a groove engages
with the pins or projections 14 or whether this engagement is effected by two
separate rings, or whether the ring 16 is caused to move by a longitudinally
adjustable pin 18 or by a pin 65 capable of rotating and provided with a screw-
thread. The latter pins may even be replaced by cords or the like as shown for
instance in Fig. 2.
From the fact of the hub 67 rotating by means of two continuation-journals
directly in the bearings of the cycle frame 68, the above-mentioned pin 18 (Fig. 1)
becomes superfluous and only one longitudinal slot 69 in the hab is sufficient to
. effect connection between the coupling pin (or latch) 28 and the sliding part 29,
arranged in the hub, by means of a pin 70.
The said part 29 carries at each end a swivel bolt 30 and 31 which enable the
cords 32 and 33, attached to them, not to take part in the rotation of the hub.
These cords are guided over pulleys 34 and 35 and may be made accessible to
the hand of the rider, pulling one cord and releasing the other effecting the coupling
of either the chain wheel 64 or 36.
In Fig. 3, showing the same method of supporting the axle as shown in Fig. 2,
the coupling of the loose wheels 37 and 38 is effected not from the space between
the spokes but from outside where annular discs 39 and 40 are secured to the hub.
The coupling pins 42 are connected with the pin 45 passing through the interior
of the hub by a disc 43 and cross pin 44, the longitudinal slots 46 allowing the
passage of and affording play to the pin 44. On the right hand side of Fig. 3,
is illustrated, as another example, a construction in which the coupling bolts 47 are
secured to a ring 48 provided with a groove. In the groove engages a ring 49
connected by means of pins 50 and cross piece 51 to the pin 45, the ring 48 not
taking part in the rotation of the pin 45. If a spring 52 is arranged behind the
pin 45, the coupling motion can be effected in the manner described and shown in
Figs. I and 5.
All separate arrangements in Figs. 1, 2 and 3 can be combined with each other.
Moreover it may be pointed out that in this device, instead of the chain wheels 1
and 2 as in Fig. 5, the wheels 3 and 4 or even 2 and 3 or 1 and 4 can also be
loose and the remaining two fast.
In Fig. 4, for instance, the driving wheels 3 and 4 are loose on the crank shaft 62
and are alternately fixed by cross wedges 53 which pass through the pin 54 in the
crank shaft and project through longitudinal slots 55 in the shaft. The wheels 3
and 4 have in their central opening grooves with which the above wedges engage.
The pin 54 is connected to a ring 63 by a pin 56, the latter passing through a
longitudinal slot 57 in the shaft. Through another longitudinal slot 58 through the
bearing 59 passes a pin 60 of a longitudinally adjustable part 61 and engages with
the groove of the ring 63. When the sliding part 61 is therefore moved in a
longitudinal direction by means of a cord or the like, the gear is changed.
All these and other similar constructions have the same characteristic feature, that
the change of gear is brought about by a corresponding movement of a rigid or
elastic part in the cycle shaft or in the hub of the wheel. By arranging said parts
in the hollow space of a shaft or of a hub, the parts which would otherwise come
in the way, such as spokes, parts of the frame and the like, are avoided, besides the
weight and space occupied by the device is thus reduced to minimum without
materially weakening the axle by boring out the part subjected to the least strain.
Further advantages are that the coupling rings are completely encased in the hub

page_text: or in the shaft bearings and thus not only are protected from dirt and dust, but
at the same time are lubricated by the oil used for the bearings.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is;
1. A device for changing the driving gear of bicycles and other vehicles characterised
by a hollow axle or hub in the hollow space of which any desired rigid or elastic
parts may be placed by means of which parts driving couplings of any desired kind
may be thrown into or out of gear.
2. The combination and arrangement of parts constituting variable speed driving
mechanism for bicycles and other vehicles substantially as shown and described with
reference to the accompanying drawings.
Dave 1 day of August 1990.
BOULT & WADE,
Agents for the Applicant.
BOULT & WADE,
Agents for the Applicant.