An Improved Means for Propelling Bicycles.
Year: 1899

page_text: :
Date of Application, 15th Sept., 1000
Complete Specification Left, 9th Dec., 1899-Accepted, 27th Jan., 1500
:
Complete Specification Left, 9th Dec., 1899-Accepted, 27th Jan., 1500
PROVISIONAL SPECIFICATION.
An Improved Means for Propelling Bicycles.
We, GEORGE EDWIN TISSINGTON, of Renwick Street, Drummoyne, Sydney,
New South Wales, Engineer, and JAMES RICHARD THOMSON, of Union Bank
Chambers, 68, Pitt Street, Sydney, New South Wales, Consulting Engineer,
do hereby declare the nature of our invention to be as tollows:-
Our invention consists in using an elliptical driving wheel, instead of a round
driving wheel, to transmit the power by means of a driving band or chain, to
the driven wheel, with the cranks in or near the line of the short axis. The
object being to reduce the speed of the cranks in those parts of the revolution
where the maximum power can be applied, so that, that power may dwell thereon
to more advantage, and to increase the speed of the cranks in those parts of
the revolution where the power can not be so advantageously applied, which
we consider to be of service in ascending slopes or travelling at high speeds.
In using elliptical wheels as described, we find there is a slight variation in
the tension of the chain at certain parts of the revolution, this can be taken
up by a tightening wheel if desired.
To more fully describe our invention, a drawing is attached wherein.
A is the elliptical wheel.
12 hal
An Improved Means for Propelling Bicycles.
We, GEORGE EDWIN TISSINGTON, of Renwick Street, Drummoyne, Sydney,
New South Wales, Engineer, and JAMES RICHARD THOMSON, of Union Bank
Chambers, 68, Pitt Street, Sydney, New South Wales, Consulting Engineer,
do hereby declare the nature of our invention and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement, that is to say:-
Our invention consists in using an elliptical driving wheel, instead of a round
driving wheel, to transmit the power by means of a driving band or chain, to
the driven wheel, with the cranks in or near the line of the short axis. The

page_text: object being to reduce the speed of the cranks in those parts of the revolution
where the maximum power can be applied, so that, that power may dwell thereon
to more advantage, and to increase the speed of the cranks in those parts of
the revolution where the power can not ce so advantageously applied, which
we consider to be of service in ascending slopes or travelling at high speeds.
In using elliptical wheels as described, we find there is a slight variation in
the tension of the chain at certain parts of the revolution, this can be taken
up by a tightening wheel if desired.
To enable our invention to be fully understood we refer to the drawing ac-
companying our Provisional Specification, wherein A is the elliptical wheel.
Bis the driven wheel.
C, and C, are the cranks.
D, D, the driving band, or chain and E is the tightening wheel.
The chain tightening up roller E is carried on a moveable or sliding
bracket E mounted on the stay tube E2, and the bracket E is shifted along
the tube E which in consequence of the different diameters of wheels is on
an inclined plane, and so by this movement the chain is taken up or adjusted.
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;-
First. A driving wheel of unequal diameters, and of mor or less an elliptical
form, in combination with the usual endless connecting band or chain and
driving wheel, substantially as set forth.
Datad the th of December 1899