Improved Chain Gearing suitable for Cycles.
Year: 1897

page_text: Date of Application, 15th Mar., 1897-Accepted, 17th Apr., 1897
Improved Chain Gearing suitable for Cycles.
I, JOHANES OTTO SAHLMANN, of 4, Grindelweg, Hamburg, Germany,
Mechanician, 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 the improvements that have hitherto been made in chain-gearing for cycles
have had the drawback that, especially in wet or rainy weather, the operation of
the pedals has been rendered by them considerably more difficult and sometimes
impossible.
This disadvantage is due in almost every case to the fact that inside the chain
there are spaces and cavities between the links in which the dirt of the roads can
easily accumulate. The accumulation of dust and dirt in combination with the oil
used for lubricating the joints constitutes a very great hindrance to the flexibility
of the chain, whilst the teeth of the chain-wheel and the chain itself are subjected
to great wear and tear.
All these disadvantages are avoided in a simple manner by my improved gearing
which presents no coign of vantage to the above mentioned hindering and destroying
agencies, and ensures an exact meshing of the teeth with the chain, thereby
ensuring the transmission, without appreciable loss, of the energy exerted in operating
the pedals.
Figs. 1, 2, and 3 of the accompanying drawings represent the chain, larger than
it actually is, in elevation and section.
Fig. 4 represents a chain-wheel with a portion of the chain in the actual size.
The chain comprises outer links a and inner links b. The latter are each
composed of two plates c which are connected firmly together by means of hollow
pins or bushes d. Around the bushes d are loosely mounted, so as to be capable
of turning antifriction-rollers e which at their peripheries are fluted parallelly to
their axes, in saw-like fashion. The ends of the plates c fit accurately in the
cranked links a in such a manner that the inner sides of the chain form straight
lines without any deviations, prominences, or recesses. The links are connected
together by means of pins f, the ends f₁ of which are secured in a known manner
by riveting or otherwise after the chain has been put together. Fig. 1 illustrates
the chain put together. Fig. 2 shows the several links moved apart, the inner
links b being loosely put together without antifriction-rollers e. The latter are
shown in Fig. 1 in side elevation and in section, and in Fig. 3 in end elevation.
The chain-wheel (Fig. 4) is formed with correspondingly shaped teeth ¹, which
are similarly fluted or roughened in saw-like fashion at their operative surfaces.
The effect of this arrangement is to prevent the chain from slipping on the wheel,
and to ensure the uniform rolling of the antifriction-rollers on the faces of the
teeth so that the force exerted upon the chain will be transmitted to its full
extent to the axle of the rear-wheel.
It will be obvious that if the chain-wheel. is to rotate in both directions, both
sides of each of its teeth may be roughened or fluted in the way described.
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. Chain gearing comprising a chain-wheel / whose teeth are fluted or

page_text: roughened on one or both sides in saw-like fashion, and a pitch-chain which is quite
plane on the inside and bas rollers e fluted or roughened in saw-like fashion.
2. Chain-gearing constructed arranged and operating as herein before described
with reference to and shown in the accompanying drawings.
Dated this 15th day of March 1897.
F. WISE HOWORTH,
46 Lincoln's Inn. Fields, London, W.C., Agent for the Applicant.