Improvements in and relating to Chain Driving Gear.
Year: 1898

page_text: QUALE LEIE DIEUIFICATION.
Improvements in and relating to Chain Driving Gear.
I, ADRIEN ALEXIS AMAN SAINTE, of 93, Rue Oberkampf, Paris, in the Republic
of France, Civil 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 chain driving gear, whereby motion can be trans-
mitted between two shafts without the use of toothed or sprocket chain wheels
such as ordinarily employed.
The usual construction of driving chain although good as a transmitter when first
used stretches by degrees, which prevents it from taking properly into the teeth
of the sprocket wheels with the result that the pace is not the same and breakage
of the chain or of the teeth of the wheels often results.
These disadvantages are overcome by my improved gearing which is illustrated
in the accompanying drawings, wherein :-
Figure 1 is a side elevation of the said mechanism.
Figure 2 is a section on 1-2 of Figure 1.
Figures 3 to 6 show in plan different constructions of driving chains according
to my invention.
The chain of my improved driving mechanism is composed of ordinary links a
the connecting pins a of which form axles for a series of wheels or rollers A
revolving on the said axles with slight friction.
These rollers A may be mounted on each succeeding axle a¹ or be arranged at
wider intervals around the chain.
The said rollers are narrower at their rims a than at their bosses a³ so that they
are tapered or wedge shaped in section, and are adapted to work in corresponding
grooves in the pullies B C.
The links a of the chain may, as in an ordinary chain, be either single as shown
or be double or multiple. In the arrangement shown in Figure 3 there is one
roller only on each of the axles which carry such rollers.
In the arrangement shown in Figure 4 however the rollers are arranged in sets
of three on the same pin or axle a' thus forming three series of rollers each en-
gaging in corresponding grooves in the rims of the pulleys B, C. It will be seen
that in this arrangement the axles project beyond the links a so that the rollers
at the ends of the axles are outside the chain.

page_text: The ends of the axles may however be secured in the links of the chain if
desired. As shown in Figure 5 the rollers A are arranged to alternate with one
another, that is to say they are arranged in echelon and in this case the chain
is shown as having four series of links a.
The rollers A may also be arranged side by side without any links a between
them as in Figure 6, in which case if desired all the rollers on the same pin or
axle may be formed integrally with one another.
Moreover a number of rollers might be formed integrally with one another.
It is evident that the chain might be composed of any desired number of rows of
links, with a corresponding number of rows of rollers between them.
The rollers engage or bind in the grooves of the pulleys B C and act by friction
so that the transmission is produced without shock and should the chain become
stretched the motion will still continue even though the stretching is considerable.
E is a single tightening roller which can be pressed on to the chain by any
suitable means so as to enable the proper tension of the latter to be obtained.
Or means for adjusting the two pulleys B C further apart might be employed to
tighten up the chain. The rollers instead of having wedge-like peripheries might
have V-shaped grooves, and the pulleys might have wedge-like or tapered peri-
pheries or projections to engage in these grooves. These conical rollers could of
course be arranged in the same manner as those before referred to.
The action of my improved driving gear is as follows:-
If the chain be slack, it will have no driving power as the rollers which come
into contact with the grooved pulleys will simply turn on their own axes with very
slight friction. If however the chain be stretched tight either by a stretching
roller or otherwise, the rollers will wedge or bite into the grooves of the pulleys,
and the driving will take place.
It thus follows that, if the chain is gradually stretched, the rollers A will
gradually wedge in the grooves of the pulleys and consequently transmit the motion
gradually and without shock.
To compensate for stretching of the chain, some of the links may be made larger
than others, so that, when stretching has taken place, it is only necessary to replace
one or two large links by some of ordinary size or smaller.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. A driving chain carrying rollers adapted to exert a wedging action on the
rims of the pulleys over which the chain runs, substantially as and for the purposes
described.
2. A chain of the kind referred to having single or multiple links the connecting
pins of which serve as axles for the rollers which may be arranged in one or
more rows, said rollers being either tapered or wedge-shape in section to engage
corresponding grooves on the pulleys, or provided with grooves adapted to engage
wedge-shaped rims or projections on the pulleys substantially as described.
3. My improved chain driving gear constructed substantially as herein before
described with reference to Figures 1, 2 and 3 of the annexed drawings.
4. The modified forms of driving chain constructed substantially as described
with reference to Figures 4, 5 or 6 of the annexed drawings.
1 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.