Improvements in Covers for the Chains of Bicycles and for Driving Chains for other purposes.
Year: 1897

page_text: Date of Application, 23rd Sept., 1897-Accepted, 27th Nov., 1897
COMPLETE SPECIFICATION.
Improvements in Covers for the Chains of Bicycles and for Driving
Chains for other purposes.
;
I, WALTER, EDOUARD FELIX MARCHAL, (signing as W. Marchal) of 11 Avenue
Daumesnil St. Mande Seine in the French Republic, Wholesale Wine Merchant
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 follow-
ing statement:-
. My invention relates to a chain-cover for the chains of cycles, auto-motors, and
generally for all transmission chains which need protection against dust, damp,
mud, and the like.
My invention is based in principle on the employment of an elastic tube, pre-
ferably of india-rubber, of transverse circular, elliptical or polygonal closed section,
open throughout its length (along a generating line) and furnished with suitable
slots on the edges of the slit in order to allow of its being closely applied to the
chain and suitably adjusted.
The
The two ends of the slit tube are joined together in any suitable manner.
length of the chain-cover thus formed must be slightly smaller than the length of
the chain, so that the slight tension and the bi-lateral pressure caused by the
tendency of the elastic material to resume its original closed section (being the
tendency of the edges of the tube to come together again), suffices amply for keep-
ing the chain-cover on the chain. Not only is no fastening of the chain-cover
to the chain thus necessary, but such would be in fact objectionable, the apparatus
when in action passing over a slightly less distance than the chain, whence results
a continuous friction and an automatic cleaning.
In order that my invention may be understood I annex a drawing to the present
description. In this drawing
Fig. 1 is a perspective view showing the application of the chain-cover form-
ing my invention to the chain of a safety bicycle.
Fig. 2 is a perspective view, on a larger scale, of a piece of tube of circular
section, before the opening has been effected along the generating line, the cut
first made being indicated by the letters XX.
Fig. 3 is a similar view of the tube after being cut and opened and provided
with the slots; this figure shows the natural shape assumed by the tube when the
chain is not attached thereto.
The two edges or lips a a of the tube A when in use press against the sides of
the chain B, so that no other fastening is necessary.
In order to allow the chain-cover to follow the movement of the chain and to
remain properly attached thereto during the rotation of the wheels or pinions,
suitable slots a are formed at certain regular intervals in the edges of the chain-
cover A. These slots may be of any suitable form. In the drawing I have
shown them as being of V-shape with a circular opening at the top.
Fig. 1 shows, without the necessity of further explanation, how these slots

page_text: allow the chain-cover to adapt itself to the different curves or indentations of the
chain.
As I have previously stated, the idea of forming the chain-cover by means of a
tube of originally closed transverse section, enables me to dispense with the use
of fastenings, so that the chain-cover is free to slide longitudinally on the chain in
motion (which actually occurs in practice) and produces an automatic and
continuous cleaning of the chain.
The chain-cover constituting my invention is exceedingly light, very inexpen-
sive, very easy to put on and take off. I am aware that india-rubber chain covers
similar to mine have been employed already but such are not formed' of a tube
of originally closed transverse section but on the contrary have a U shape profile,
so that the edges have no tendency to press against the chain and consequently
fastenings are generally necessary; hence the automatic cleaning during the work-
ing of the chain cannot be effected.
In conclusion I would observe that I have only given the annexed drawing
by way of demonstration and that my invention may be carried out in many other
ways. Thus, for example, instead of soldering or fastening together the ends of
the slit tube to form a continuous chain-cover, I can make the tubes endless;
and instead of employing a tube of circular section, I can make use of a tube
of originally elliptical or polygonal section, for instance hexagonal, octagonal,
etc; whilst instead of making the tube of india-rubber I can make use of a tube
of any suitable elastic material or composition.
It will be easily understood, from the foregoing that the chain cover can be
applied not only to cycle chains, but to transmission chains of other kinds.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
11
1. A chain-cover formed from a complete tube of elastic material which is subse-
quently slit along its length and provided on the edges so formed with slots tó
allow it to follow the movement of the chain the construction enabling the cover to
embrace the chain substantially as and for the purpose described;
[
2. The improved chain-cover constructed substantially as described and illus
trated.