Improvements in the Adjustment of Driving Chains of Velocipedes
Year: 1895

page_text: Date of Application, 3rd July, 1895
Complete Specification Left, 29th Oct., 1895-Accepted, 7th Dec., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Adjustment of Driving Chains of Velocipedes.
I. SAMUEL WINFIELD BANNISTER of 7 Colwick Street Nottingham Engineer
do hereby declare the nature of this invention to be as follows:-
My invention relates to improvement in the adjustment of driving chains of
velocipedes by means of eccentric washers or bushes fitted on the outer ends of
the driving wheel axle in such manner that by turning the aforesail axle washers
or bushes round, a varying distance may be obtained between the centres of the
chain wheels thereby giving an adjustment of the driving chain.
In place of eccentric washers or bushes, the aforesaid axle may have one or two
collars solid and turned eccentric with same.
Dated this First day of July 1895.
SAMUEL WINFIELD BANNISTER.
Improvements in the Adjustment of Driving Chains of Velocipedes.
SAMUEL WINFIELD BANNISTER 7 Colwick Street Nottingham Engineer do
hereby declare the nature of this invention and in what manner the same to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to improvements in the means by which the tension of the
driving chain used in velocipedes of the kind known as rear driven cycles may be
adjusted or regulated, the invention being applicable to safeties, tandems and other
similar cycles.
In machines of the kind referred to as at present constructed the axle of the
back wheel is generally so arranged that it can slide in slots formed in the back
legs or stays of the cycle frame, and the tension of the chain is adjusted by means
of two screws, one at each end of the axle. When adjusting the tension of the
driving chain with this arrangement each end of the wheel axle has to be moved
separately and there is a liability of the back wheel being drawn out of line
with the front wheel, the adjusting screws are liable to be bent, and in many
cycles it is difficult to turn the nuts on the same.
Now the object of this invention is the provision of means for enabling both
ends of the back wheel axle to be moved to or from the crank axle an equal
distance at the same operation which may be performed at either end of the
axle, and the arrangement of such means by which the objections to the existing
means are overcome.
According to this invention the ends of the back wheel axle are provided with
eccentric washers or bushes which are fitted to turn in bearings carried by the
cycle frame and held in their placed position by nuts on the ends of the axle.
Holes or slots are provided for turning the washers or bushes in their bearings.
and the rotation of the same carries the axle and wheel to or from the crank axle
thus varying the distance between the two axles, and at the same time adjusts or
regulates the tension of the driving chain.

page_text: In the accompanying drawings which are referred to hereafter,
Fig. 1. is a vertical section of a back wheel hub fitted with the improved means
for varying the tension of the driving chain, and
Fig. 2 is an end elevation of the same with one of the nuts and washers
removed.
The wheel hub a is fitted in the usual way with ball bearings and a chain
wheel c.
The cones d d are also of the usual description and either of them may
be fixed upon the axle t.
Outside the cones d d' the axle is squared at e and the extreme ends screwed for
the nuts g
In the arrangement shown, each square e is fitted with two eccentric
washers which are of two diameters and 2, whereof the latter is fitted within
a circular bearing k carried by the back stay ', while the annular rim between
the two diameters bears upon the faces of the bearing k. The washers are
provided with slots h³ for a key, and are so arranged that when in position in
the bearings there is a space between them to allow of them being tightened
up to the faces of the bearing k by the nuts 9.
Both ends of the axle are fitted in the same way, so that it is impossible for the
axle to turn about its own centre, but when the washers at one end of the axle
are rotated, the washers at the other end of the axle are similarly rotated, and
the axle moved in a circle which has a radius equal to the distance between the
centre of the axle and the centre of the washers. This rotation of the axle
about the centre of the fixed bearings k moves the back wheel with the chain
wheel to or from the driving chain wheel on the crank axle, and by varying
the distance between the two axles regulates or adjusts the tension of the driving
chain.
Preferably the bearing is made from a wrought iron stamping which is brazed
to the back stay and has a lug to which the back leg may be bolted, but
the bearing may be constructed by other known methods.
In modifications of this invention one of the eccentric washers may be rigidly
fixed to the axle or there may be a central eccentric bush between two eccentric or
other washers at each end of the axle. The slot may be replaced by holes,
pius, or the like and the key shaped to correspond while the spindle may be
compelled to turn with the washers by means of squares as shown or by flats, keys
or similar mechanical devices.
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. The provision of means of the kind herein set forth, when applied to
safety, tandem and similar cycles for enabling the axle of the back wheel to be
moved parallel to itself by a single operation performed at either end, as and for
the purpose herein declared.
2. In rear driven safety, tandem and similar cycles, connecting both ends of the
axle of the back wheel to eccentric washers or bushes, so arranged that if either
washer or bush is rotated in its bearing, the other washers or bushes at the opposite
end of the same axle are rotated simultaneously and equally, and the axle moved
parallel to itself as herein set forth and for the purpose declared.
3. The general arrangement and construction of the mechanisın herein described
with reference to the accompanying drawings when applied to safety tandem and
similar cycles for the purpose herein declared.
Dated this 26th day of October 1895.
W. H. POTTER, M.L.M.E.,
Nottingham, Patent Agent.