Improvements in Gear Cases for Cycles and the like.
Year: 1897

page_text: Date of Application, 26th Aug., 1897
Complete Specification Left, 26th May, 1898-Accepted, 26th Aug., 1898
Improvements in Gear Cases for Cycles and the like.
We, GUSTAV REICH, and CARL TEISE, of the Offenbacher Celluloid and
Vulcanite Works, Offenbach-on-the-Main, in the Empire of Germany, Manu-
facturers, do hereby declare the nature of this invention to be as follows:-
None of the gear cases at present employed for protecting the chains of cycles
against the penetration of dust and for rendering possible a good lubrication,
have been an entire success in practice. Makers endeavour to limit the use
of gear cases as far as possible, as the attachment itself of the same requires
considerable time and trouble, and further the defective stability of the present
cases causes constant repairs and thereby great dissatisfaction. The difficulties
presented in the production of a really practical and useful gear case are caused
mainly by the fact that cycle frames vary very considerably and the gear
case must also be made to be adjusted to suit any stretching of the chain. It
must also be very light and yet so rigid that it neither shakes nor causes any
friction on the moving parts.
This invention has for its object a gear case, the actual construction of which,
whilst avoiding all the drawbacks herein before mentioned meets all the require-
ments of such an appliance. It is, in contrast to other gear cases, entirely con-
structed of celluloid and has a rigidity or stability not hitherto attained.
Further, it possesses the great advantage that in it all dead space is avoided,
such dead space causing in the old form of gear cases a. highly unpleasant noise.
Finally, it must be stated that the construction of this improved gear case
allows of its being applied to any machine in a few minutes without any practical
knowledge, or of being opened or easily taken off for the purpose of cleaning,
repairs or the like.
The improved gear case consists of an inner plate made in three parts and
of an outer plate. The centre part of the inner plate is fastened to a bar of the
frame by means of suitable bands, clamps or the like which are passed through a
suitable slot. The two other parts are also provided with slots so that they
may be pushed laterally over the corresponding axles. They are attached to
the central piece by means of screws and suitable washers. The whole inner
plate is so stamped out that its central part coincides with the outer plate which
is stamped out in a similar way and only leaves free a completely enclosed space
for the chain wheels, chain and the passage of the frame bars. The edge of both
plates is bevelled off so that the one plate may be fitted into or over the other
after the manner of the lid of a box. Instead of this arrangement however any
other suitable method such for instance as a flange connection may be employed.
The attachment of the lid is effected by means of screws which also hold together
the separate parts of the inner plate, small wing nuts or the like being employed.
Further the whole case is so formed at the top of its rear end that it embraces
the frame bar, a clamp ring being here passed round the said bar, which clamp
ring completes the fastening of the whole case. In order that the gear case may

page_text: allow of an adjustment of the chain a slot is provided in the outer plate through
which slot the rear axle nut can be reached, and this slot is covered by a cover
plate. If it be desired to reach the chain for the purpose of cleaning, repairs
or the like, it is only necessary to release the screws, holding together the
separate parts of the inner plate and the clamp ring, when the front plate can 5
then be easily taken off.
Dated this 25th day of August 1897
We, GUSTAV REICH, and CARL FEHSE, of the Offenbacher Celluloid and
Vulcanite Works, Offenbach-on-the-Main, in the Empire of Germany, Manu-
facturers, 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:-
Next to the pneumatic tyres, the chain as is well known is the weak point in
cycles, and efforts to replace the same have hitherto not yet been successful
in spite of all endeavours. The chain is precisely the member of the cycle which
most requires a good lubrication but which is most endangered through lubri-
cation, as the dust, unavoidably present combines with the oil to form a paste
which not only effects its destructive work in a very short time but also largely
removes the advantages of the lubrication.
In order to avoid these great drawbacks efforts have been made to surround
the entire chain with a protective casing or gear case. Great difficulties have
however so far arisen against this, as almost every frame differs, and also the
gear case must be so arranged that it may be adjusted to correspond with
the stretching of the chain. Great difficulties also arose in the choice of suitable
materials. Of metals only aluminium could be considered, which however does
not possess the necessary sufficient stability. Celluloid appears to be the most
suitable material but it has not yet been possible to make gear cases entirely
of celluloid without the assistance of other materials such as wood, metal or
the like to render them sufficiently rigid.
This invention has for its object a gear case the peculiar construction and
method of fastening of which renders it possible to not only fit to nearly all
the present forms of cycle construction but also allows of its being made entirely
of celluloid and with a stability or rigidity hitherto unattainable.
Further, it possesses the great advantage that in it all dead space is avoided,
such dead space causing in the old form of gear cases a highly unpleasant noise.
Finally, it must be stated that the construction of this improved gear case allows
of its being applied to any machine in a few minutes without any practical
knowledge, or of being opened or easily taken off for the purpose of cleaning,
repairs or the like.
A form of construction of this improved gear-case is shown in the accompany-
ing drawings, in which:-
:-
Figure 1 shows it fitted to a bicycle;
Figure 2 a side view of the inner plate in three parts;
Figures 3, 4 and 5 separate views of the three parts in elevation and cross
section respectively, and
Figure 6 a side view of the outer plate.

page_text: As may be seen therefrom this improved gear case consists of an inner plate
made in three parts a, b, c and of an outer plate d. The centre part 6 of the
inner plate is fastened to a bar f of the frame by means of suitable bands,
clamps or the like which are passed through a suitable slot e. The two other
parts a and c are also provided with slots g and h so that they may be pushed
laterally over the corresponding axles. They are attached to the central piece
by means of screws i and suitable washers. The whole inner plate is so stamped
out that its central part coincides with the outer plate d which is stamped out
in a similar way and only leaves free a completely enclosed space for the chain
wheels, chain and the passage of the frame bars f and k. The edge of both plates
is bevelled off so that the one plate may be fitted into or over the other after
the manner of the lid of a box. Instead of this arrangement however any other
suitable method such for instance as a flange connection may be employed. The
attachment of the lid is effected by means of screws which also hold together
the separate parts of the inner plate, small wing nuts or the like being employed.
Further the whole case is so formed at the top of its rear end that it embraces
the frame bark, a clamp ring (Fig. 1) being here passed round the said bar,
which clamp ring completes the fastening of the whole case. In order that the
gear case may allow of an adjustment of the chain a slot m is provided in the
outer plate through which slot the rear axle nut can be reached, and this slot
is covered by a cover plate. If it be desired to reach the chain for the purpose
of cleaning, repairs or the like, it is only necessary to release the screws i,
holding together the separate parts of the inner plate and the clamp ring!,
when the front plate can then be easily drawn off as far as the pedal which
will be sufficient to afford access to the chain. Of course by removing the
pedal the front plate & could be completely taken off.
It is self evident that the improved gear case hereinbefore described may
undergo various other small alterations in its construction, for instance it may
be so arranged that the rear end of the front part is made separate and then
comes to lie behind the frame bar k instead of in front of it. In such case
it remains on when the front part is removed and if the step shaped projection
of the edge be dispensed with the latter may engage down to the bottom of the
other part whilst nothing is otherwise altered in the construction.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is: -
1. A gear case, characterized by the inner plate being formed of three
parts (a, b, c), the central one (b) of which is adapted to be attached to the
horizontal frame bar (f) of the cycle and holds the two other parts (a and c),
whilst the outer plate (d) engages like a box lid in or over the inner plate,
substantially as herein before described.
2. A gear case arranged in such a way that the inner and outer plates lie
flat to one another in the centre and only allow room for the chain wheels,
chain and frame bars, substantially as hereinbefore described.
Dated this 25th day of May 1898
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.