AN IMPROVED VARIABLE SPEED, AND POWER GEAR FOR TRICYCLES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I WALTER GEORGE FREDERICK WEBSTER of N° 34 Tontine Street, Folkestone
in the County of Kent Engineer do hereby declare the nature of my Invention for
AN IMPROVED VARIABLE SPEED, AND POWER GEAR FOR TRICYCLES to be as
follows:-
In carrying out my Invention I employ on the crank axle a wheel the rim of
which is free to expand and contract to certain dimensions above and below the
size of the wheel fixed on the main axle; to convey motion from one wheel to the
other I use or flexible band of Gutta-percha, steel or other suitable material-In
order to take up the slack which must necessarily arise when the size of the wheel
on the crank axle is contracted, I provide a loose wheel running on a stud which is
free to move upd down in a slot in the frame, and so take up the slack of the
band as it arises This loose wheel may be manipulated either automatically by a
spring, or by a lever under the control of the rider.
I construct my expanding wheel and its manipulating mechanism as follows,-
on the axle I fix a disc having four or more radial slots in it. Fitting into these
slots are four or more sliding pieces carrying segments that form when the wheel
is at its smallest diameter, a complete circle, In the centre of the slots I mount
small pins placed radially and running on centre points at the rim and boss of the
disc. These pins are screwed to receive the sliding pieces which are provided with
holes, tapped with corresponding threads. When these screw. pins are made to
revolve the sliding pieces move radially either in or out according to the direction
in which the pins are turned, On the bottom of each screw pin, near the boss of
the disc I fix a small pinion; these pinions gear into a bevel wheel running loose
on the axle It will thus be seen that if this bevel wheel be held stationary while
motion is given to the crank axle the sliding segments with move radially either in
or out according to the direction in which the axle is moving.
To hold or release the bevel wheel I cut a series of teeth round the face of the
boss of the wheel and provide a small lever conveniently fixed for manipulation by
the rider to engage in these teeth, and it will be obvious that the extent to which
the rim of the wheel will be expanded or contracted will depend entirely upon the
length of time in respect to the movement of the crank axle, that the loose bevel
wheel is held stationary.

page_text: I WALTER GEORGE FREDERICK WEBSTER of No. 34 Tontine Street Folkestone,
in the County of Kent, Engineer, do hereby declare the nature of my said invention
for "AN IMPROVED VARIABLE SPEED & POWER GEAR FOR TRICYCLES," and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Since filing my Provisional Specification I have made such further improvements
in the construction of my expanding wheel, for which improvements I have made
another application for a Patent No. 7765-1884, that I deem it expedient to
abandon the particular construction of the expanding wheel as described in my
provisional specification & limit the extent of my invention as covered by this
application to the method of taking up the slack of the chain which must
necessarily arise when the size of one or other of the chain wheels is contracted.
I provide a loose or "idle" wheel running on a stud which is free to move up
& down in a slot in the frame, & so take up the slack of the band or chain as it
arises. The loose wheel may be manipulated either automatically by a spring, or
by a lever under the control of the rider.
As the function of this idle wheel is but to keep the chain taut on the slack
running side, it will be obvious that it may be mounted in many different ways to
attain the same end, & as I do not purpose claiming any particular method of
applying it, it will not be necessary to annex to this specification any drawings.
I am aware that "idle" pulleys have been used for a considerable time for taking
up the slack of bands or chains but I believe that they have never been applied to
tricycles & my invention is therefore limited to the application of a known
contrivance to a new use.
Having now particularly described & ascertained the nature of my said
invention, & in what manner the same is to be performed, I declare that what
I claim is; The application to a Tricycle of a loose or "idle" wheel in conjunction
with any expanding chain wheel for taking up the slack of the chain or band, when
such expanding wheel is contracted.
1801.
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer & Patent Agent,
Royal Courts Chambers,
70, 71, & 72, Chancery Lane, London, W.C.,
Agent for the Applicant.