Improvements in Changeable Gear for Cycles.
Year: 1898

page_text: Date of Application, 6th July, 1898-Accepted, 22nd Oct.,
1898
COMPLETE SPECIFICATION.
Improvements in Changeable Gear for Cycles.
I, JOHN WILHELM ORTLEPP, of No. 119, Marktstrasse, St. Pauli, Hamburg,
in the German Empire, Mechanical 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:-
This invention relates to apparatus by means of which the gear of cycles can
be changed during riding. For this purpose the chain wheel transmitting the
power is supported in bearings independent from the crank axle, and the crank
axle is movable in a guide so that an eccentric movement and a movement side-
ways may be given to it for engaging and disengaging.
By this arrangement I obtain the advantages of an easily changeable gear
without the use of two chains and the application of fragile parts; these advantages
being as is well known, that a high gear may be used on a smooth level road,
and low gear on hilly roads, or when riding against wind, or under similar
circumstances.
In order that this invention may be the better understood, I now proceed to
describe the same with reference to the accompanying drawings and to the letters
and figures marked thereon.
Figure 1 shows a longitudinal section.
Figure 2 is a right hand side view, partly in section.
Fig. 3 is a left hand side view the crank being omitted.
Figure 4 is a sectional view on the line 1--1 of Figure 1, showing the mechanism
when used for high gearing.
Figure 5 is a part sectional view.
Figure 6 is a sectional view on the line 2-2 of Figure 5.
Figures 7 and 8 are sectional views on the lines 3-3 and 4 4 of Figure 5
of the mechanism used for low gearing, the chain wheel being omitted.
Figure 9 shows a longitudinal view of the crank bearing.
Figures 10 and 12 show sectional views on the lines 5-5 and 6-6 of Figure 9.
Figure 11 is a side view of the crank bearing.
Figure 13 is a part sectional side view of the chain wheel bearing and the crank
bearing guide.
Figure 14 is a part sectional front view thereof.
Figure 15 is a sectional view on the line 7-7 of Figure 14, the chain wheel
being omitted.
As shown in Figures 9 and 10, the crank axle a is elongated at one side, where
it carries a cog wheel e beside the crank b. The crank d is of the ordinary shape,
but the crank 6 has a projection e protruding inwards and carries at its inner
end a dust protector 6. The axle a rests in ball bearings of the bearing box f
provided with the usual cones, and fixed eccentrically in a box g as shown in
Figures 11 and 12. A pin h protrudes over the edge of the last named box g,
a lever being attached to the side thereof, adapted to move the whole system.
This movement takes place in the sleeve k which as shown in Figure 14 is pro-
vided with a slot in which the pin h of the crank bearing system is adapted to

page_text: slide. The attachment of the sleeve k to the frame is effected in the usual manner
by clamping it in a slotted sleeve or the like and is omitted in the drawings to
simplify the latter. A ball bearing is attached to the sleeve the centre of the
bearing being however outside the centre of the sleeve: it is designed to carry the
chain wheel m. The chain wheel m is secured by means of bolts m', Figures 1, 55
and 14, to the casing m² of the ball-bearing 1. A casing or disc n is also secured to
the casing m² by means of bolts o', in which are recesses ¹ Figure 13, and between
which are arranged small rollers o, the distances between which correspond with
the division of the cog wheel e fixed to the axle a with which they are adapted to
engage.
The action of the mechanism is as follows:-
Supposing the road to be smooth and level and the rider desires to ride with a
high gear. In this case the parts occupy the position as shown in Figures 1 to 4.
The pin h of the crank bearing box g is in the slot k¹ of the guiding box k, which
slot is at this part inclined or diverted to the left side. Therefore, the crank
axle a is in the centre of the ball bearing on which the chain wheel m runs.
The cog wheel c situated on the elongated end a of the crank axle moves freely in
the hollow of the bearing 7, the crank bengaging with its projection e into one of
the interstices n¹ of the disc or rim n rigidly connected as above described with the
chain wheel m. Therefore while pedalling, the chain wheel m must be rotated, and
the gearing will be that corresponding to the number of cogs of the chain
wheel m.
When the rider desires to ride with a low gear he pulls a cord or rope, passing
from the upper horizontal frame rod to the lever i or any suitable system of
levers, or equivalent devices. In consequence the sleeve g of the crank bearing. will
move spirally, according to the form of the slot k¹, into the sleeve k. During this
operation the projection e of the crank b leaves first the slot n¹. Therefore in this
position the chain wheel m can rotate freely on its bearing 7. At the same time the
C has moved
cog wheel
out of the hollow of the ball bearing
and is opposite to one of the small rollers of the treadle
o
with which it engages during the further rotation of its eccentrically
Therefore in this
situated axle system, as shown in Figures 7 and 8.
position the chain wheel m is not driven directly from the crank b, but indirectly
by means of the roller toothed gearing and the intermediate cog-wheel c.
lowering gear depends upon the number of small rollers of the rim n and of the
teeth of the cog wheel c.
gear
The
As the roller toothed gear used for giving a lower gear works almost without
friction no appreciable loss of driving power takes place. On the contrary the
effect of this transmission compared with the usually applied systems will be
better, because the bearing of the chain wheel is not one-sided, the power being
taken up by the balls in the centre of gravity of the system almost without friction.
The pins of the gearing are protected against wear and tear by the intervention of
the rollers placed over them and the cog wheel c can be easily exchanged if desired.
As there are no other parts subject to wear, it will be apparent that the object of
the invention, to change the gear of a cycle according to the nature of the road
and other circumstances is attained to the greatest satisfaction of the rider by this
mechanism.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1st. Apparatus for lowering the gear of cycles in which the bearing f of the
crank axle is situated eccentrically and can be moved sideways and also around its
centre, whereby either a cog wheel c situated on an axle a elongated at one
side engages with a roller wheel o, or a crank 6 situated on the same elongation
of the axle a engages by a projection e with a recessed cam disc n n¹, the said

page_text: systems being arranged on the chain wheel m supported in separate bearings,
substantially as described.
2. A gear as claimed in Claim 1 having a crank axle bearing f fixed eccentrically
in a box g guided by means of a pin h in the slot k of a fixed box k, and adapted
to move sideways and also to be rotated around its centre, substantially as
described.
3. A. crank axle for bearings as claimed in Claims 1 and 2 one side of which
is elongated and provided with a cog wheel c and a crank having a projection e
substantially as described.
4. Apparatus as claimed in Claims 1 and 2 in which a rim n is connected to
the chain wheel m, situated in separate bearings, the said rim being provided with
rollers o inside, and with a ratchet disc, having recesses n¹ outside for the purpose
of being operated either by a cog wheel c situated on the axle a or by the
projection e of the crank d substantially as described.
Dated this 6th day of July 1898.
FELL & JAMES,
Agents for the Applicant.