Improvements in Driving Gear for Velocipedes.
Year: 1891

page_text: Date of Application, 26th Nov., 1891
Complete Specification Left, 25th Aug., 1892-Accepted, 1st Oct., 1892
PROVISIONAL SPECIFICATION.
Improvements in Driving Gear for Velocipedes.
We WILLIAM THOMAS SHAW, ISAAC WATTS BOOTHROYD Directors and
ARTHUR SYDENHAM Engineer & Works Manager of the Crypto Cycle
Company Limited 64, City Road, London, E.C. do hereby declare the nature
of this invention to be as follows:
Our invention consists in an improved construction of driving gear for bicycles
and for tricycles which are propelled by a single driving wheel; and its object
is to enable a rider to drive a wheel by direct application of power through a
central crank-axle, but that such wheel by means of the gearing described below
shall be caused to rotate at a higher velocity than that of the crank-axle. The
effect of this is that a rider whose length of leg limits him to a comparatively
low wheel is enabled to ride a wheel the diameter of which is virtually increased
to any desired extent by the intervention of the gear, whereby his speed is greatly
increased. Various Letters Patent have already been granted to ourselves and
others for inventions of this nature. Our present improvements relate mainly
to the mode of constructing and attaching the gear to the centre of the wheel
so as to be readily inserted in and removed from the wheel without disturbance
of the latter and with convenient means of adjustment throughout. Its con-
struction is as follows:-
The fork-ends in which the road wheel runs are provided on either side with two
ball bearings. One, which is smaller than the other, is cylindrical in form; the
other and larger bearing is annular in form and encloses the smaller bearing with
which it is excentric. The small bearings are constructed on the outside of the
fork-ends and carry the crank-axle. The larger ones are formed on the inside of
the fork-ends respectively and carry the ends of the wheel hub on which is formed
a coned ball-race. It will be seen therefore that the crank-axle and the wheel
revolve independently of each other, the axle falling excentrically within the hub
of the driving wheel. The manner in which the axle and the hub are connected is
as follows:-
On one side of the wheel the hub-flange is of the ordinary construction. Upon
the other, it carries a deep flange sailing over towards the fork on that side with
projecting ridge on its exterior for the reception of the spokes on that side.
Immediately beneath this ring an annular cover is screwed in with a ball-race
constructed on its inside periphery, such ball-race taking a bearing on the larger
bearing in the fork previously alluded to. The hollow spindle of the hub is con-
tinued towards the fork-end and has constructed upon it, a straight toothed spur
wheel. This spur-wheel gears with an internal toothed wheel of larger diameter
which is fixed to or formed in one piece with the driving axle. It will be evident
that the ratio of these two wheels determines the extent to which the road wheel is
speeded up. Upon the crank-axle being rotated, its internal wheel drives round
the small spur wheel with the hub and road wheel, at an increased velocity. The
two centres of the crank-axle and the hub respectively it is convenient to place in
a vertical line, but this position is not essential. The hollow spindle and flange of
the hub, with its annular cover and race, must of course be of sufficient dimensions
to admit of the excentric motion of the internal wheel and axle in relation to
the hub. This arrangement of gear wheels.. is shown in a Patent granted to

page_text: Mr. J. Wheatley in 1885 No. 3867, but our construction and arrangement of the
parts are entirely different and offer superior advantages.
Dated this Twenty-sixth day of November 1891.
WM. THOS. SHAW.
I. W. BOOTHROYD.
ARTHUR SYDENHAM.
Improvements in Driving Gear for Velocipedes.
We, WILLIAM THOMAS SHAW, ISAAC WATTS BOOTHROYD, Directors, and
ARTHUR SYDENHAM, Engineer and Works Manager, of the Crypto Cycle
Company, Limited, 64 City Road, London, E.C., 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 :-
Our invention consists in an improved construction of driving gear for bicycles
and for tricycles which are propelled by a single driving wheel; and its object is to
enable a rider to drive a wheel by direct application of power through a central
crank-axle, but that such wheel by means of the gearing described below shall be
caused to rotate at a higher velocity than that of the crank-axle. The effect of
this is that a rider whose length of leg limits him to a comparatively low wheel is
enabled to ride a wheel the diameter of which is virtually increased to any desired
extent by the intervention of the gear, whereby his speed is greatly increased.
Various Letters Patent have already been granted to ourselves and others for
inventions of this nature. Our present improvements relate.mainly to the mode of
constructing and attaching the gear to the centre of the wheel, so as to be readily
inserted in and removed from the wheel without disturbance of the latter, and with
convenient means of adjustment throughout. Its construction is as follows:
The fork-ends, F, in which the road wheel runs, are provided on either side with
two ball bearings. One, B, which is smaller than the other, is cylindrical in
form; the other and larger bearing, B B, is annular in form and encloses the
smaller bearing, with which it is excentric. The small bearings, B, are constructed
on the outside of the fork-ends, F, and carry the crank-axle, C.
The larger
ones, B B, are formed on the inside of the fork-ends, F, respectively, and carry the
ends of the wheel hub, on which is formed a coned ball-race, W. It will be seen
therefore that the crank-axle and the wheel revolve independently of each other,
the axle falling excentrically within the hub of the driving wheel. The manner in
which the axle and the hub are connected is as follows:-
On one side of the wheel the hub-flange, H, is of the ordinary construction.
Upon the other, it carries a deep flange, HH, sailing over towards the fork on
that side with projecting ridge on its exterior for the reception of the spokes on
that side. Immediately beneath this ring an annular cover, N, is screwed in with
a ball-race constructed on its inside periphery, at W; such ball-race taking a
bearing on the larger bearing, B B, in the fork, F, previously alluded to. The
hollow spindle of the hub, S, is continued towards the fork-end and has constructed
upon it a straight-toothed spur-wheel, R. This spur-wheel gears with an internal
toothed wheel, K, of larger diameter, which is fixed to or formed in one piece with
the driving axle, C. It will be evident that the ratio of these two wheels
determines the extent to which the road wheel is speeded up. Upon the crank-
axle, C, being rotated, its internal wheel, K, drives round the small spur-wheel, R,
with the hub and road wheel, at an increased velocity. The two centres of the
crank-axle, C, and the hub, S, respectively, it is convenient to place in a vertical
line; but this position is not essential: The hollow spindle and flange of the hub,
with its annular cover and race, must of course be of sufficient dimensions to admit
of the excentric motion of the internal wheel and axle in relation to the hub. This

page_text: arrangement of gear wheels is shown in a Patent granted to Mr. J. Wheatley
in 1885, No. 3867, but our construction and arrangement of the parts are entirely
different and offer superior advantages.
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
A
gear constructed and applied substantially in the manner, and for the purposes,
herein illustrated and described.
Dated thin 25th
1900
WM. THOS. SHAW.
I. W. BOOTHROYD.
ARTHUR SYDENHAM.