Improvements in or relating to Change Gearing.
Year: 1889

page_text: Date of Application, 11th June, 1889
Complete Specification Left, 10th Mar., 1890-Accepted, 12th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in or relating to Change Gearing.
I, HENRY COPPINGER of Tivoli Villas, Cork, in the County of Cork, Auditor do
hereby declare the nature of this invention to be as follows:-
The object of this invention is to vary the proportion of gearing for speed or power
and the invention is especially applicable where two pitch wheels connected by a pitch
chain are employed as for example in velocipedes, though it will be understood that
the invention is by no means confined to use upon velocipedes. In these machines it
is frequently desirable to be able to alter the gearing but this must be done without
unreasonable weight in the machine, much complication or much expense and the
following invention is intended to meet these requirements.
In carrying out my invention I employ what I may call a supplemental toothed
ring which I place upon either of the pitch wheels for the purpose of providing that
wheel with more teeth than it possesses in its normal condition. The ring may be
applied to both wheels if desired. This ring is shaped internally so as to fit on to the
existing pitch wheel and carries upon its periphery teeth of the same pitch as the
teeth of the normal wheel so that it may be used with the existing chain which will
merely require another link or so to make it of the proper length or if the chain be
used sufficiently slack with the normal wheel no extra link would be required. The
toothed ring may be made in various ways; where the pitch wheel to which it is to
be applied is outside the bearing of the shaft or wheel to which it belongs the ring
can be made solid suitable means such as one or more screws or clips or a divided
flange, a bayonet joint or the like heing provided to prevent its slipping off. In some
cases the ring is made a sufficiently tight fit to obviate this.
Where the pitch wheel to which the ring is to be applied is not accessible as in
the former case the ring must be divided into two or more segments or sections
suitably connected together so as to be capable of being placed around the existing
wheel and secured thereupon in any suitable manner. A convenient way. I find is
to make the ring in three pieces jointed together by suitable links or joints one
of which may be provided with a screw or equivalent means for the purpose of
fastening or unfastening.
This ring would be preferably made of metal but other material if sufficiently
strong and lasting may be used.
Where the wheel is in the first instance being made to accommodate this invention
the wheel itself may be made in the form of a simple hub or disc without teeth and
adapted to have a ring placed upon it, any suitable means being provided to prevent
the ring from working off or slipping. In this case the wheel or hub in question
would be provided with two or more rings to give the necessary change in gearing.
Where it is desired to alter the gearing of existing wheels to a slight extent but it
is found impracticable to do this by merely placing a ring upon one of the pitch
wheels the difficulty may be got over by placing two rings one on each wheel the
teeth of which are so proportioned as to give the necessary change.
Dated this 11th day of Inne 1889

page_text: COMPLETE SPECIFICATION.
Improvements in or relating to Change Gearing.
I, HENRY COPPINGER of Tivoli Villas, Cork, in the County of Cork, Auditor, 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 :-
The object of this invention is to vary the proportion of gearing for speed or
power and the invention is especially applicable where two pitch wheels connected
by a pitch chain are employed as for example in velocipedes, though it will be
understood that the invention is by no means confined to use upon velocipedes.
In these machines it is frequently desirable to be able to alter the gearing but this
must be done without unreasonable weight in the machine, much complication or
much expense, and the following invention is intended to meet these requirements.
In carrying out my invention I employ what I may call a supplemental toothed
ring which I place upon either of the pitch wheels for the purpose of providing
that wheel with more teeth than it possesses in its normal condition.
The ring
may be applied to both wheels if desired. This ring is shaped internally so as to
fit on to the existing pitch wheel and carries upon its periphery teeth of the same
pitch as the teeth of the normal wheel so that it may be used with the existing
chain which will merely require another link or so to make it of the proper length
or if the chain be used sufficiently slack with the normal wheel no extra link would
be required. The toothed ring may be made in various ways'; where the pitch
wheel to which it is to be applied is outside the bearing of the shaft or wheel to
which it belongs the ring can be made entire suitable means such as one or more
screws or clips or springs a divided flange, a bayonet joint or the like being
provided to prevent its slipping off. Or the ring may be made a sufficiently tight
fit to obviate this.
Where the pitch wheel to which the ring is to be applied is not accessible as in
the former case the ring must be divided into two or more segments or sections
suitably connected together so as to be capable of being placed around the existing
wheel and secured thereupon in any suitable manner. A convenient way I find is
to make the ring in three pieces jointed together by suitable links or joints one
of which may be provided with a screw or equivalent means for the purpose of
fastening or unfastening.
This ring would be preferably made of metal but other material if sufficiently
strong and lasting may be used.
Where it is desired to alter the gearing of existing wheels to a slight extent but it
is found impracticable to do this by merely placing a ring upon one of the pitch
wheels the difficulty may be got over by placing two rings one on each wheel the
teeth of which are so proportioned as to give the necessary change.
The accompanying drawings show a practical application of my invention to the
smaller chain wheel of a safety bicycle of the usual construction; this chain wheel
may either form a part of the hub of the driving wheel of the bicycle or may be
secured upon the axle of that wheel.
Figure 1 is an elevation of the chain wheel with my toothed ring upon it, the three
sections being in position but one in dotted lines turned outward as in the act of
placing or removing the ring. Figure 2 is an edge view, and figure 3 a separate side
view of one of the segments when made in skeleton form and having a larger number
of teeth upon its periphery.
Like letters indicate like parts in the different figures.
A is the chain wheel and B the toothed ring which in figure 1 is shown made in
segments as would generally be the case. In this view there are three of these
segments which are shown solid and it will be observed that these segments are so
shaped as to fit over the teeth A' of the wheel A filling up the spaces between them.
The ring is provided on its outer periphery with teeth B₁ of the same shape and pitch

page_text: as those of the wheel A so as to fit the same chain. The segments are jointed
together in any convenient manner either permanently as by the links B2 shown in
the figure or they may be formed to interlock so that when in position on the wheel A
they will be secured. In order to facilitate the application and removal of the
segments one at least of the pins or pivots B' which secure the links is made
removable and is preferably provided with a winged head or equivalent B* figure 2 so
that it may be turned by the fingers. However this may be merely an ordinary screw
head to be turned by a screw driver if preferred or some other suitable means such as
a spring device may be employed for establishing this connection.
To facilitate the application and removal of the segments portions of the corners
may be removed. Thus, in figure 1 the section B as shown by the dotted lines has
been turned upon the pivot B' consequently the corner B' of the segment would catch
upon the tooth A¹ were not a small portion of it removed, to allow of its passing.
A similar difficulty would arise in the case of the next segment where the corner B
would also require easing. In the case of the last segment, however, as that can in
almost all cases be slipped on sideways it may be made a close fit upon the teeth of
the wheel but of course any necessary provision for applying or removing the
segments or maintaining them in position may be made.
In figure 3 one of the sections B is shown in skeleton form the central portion
being omitted for the sake of lightness; otherwise this segment may be similar to
those shown in figure 1. If desired a web or flange may be carried up centrally
or at one or both of the sides so as to strengthen this skeleton form or give it
the appearance of being solid; in the latter case the interior may be used for
containing lubricant and in that case holes may be provided to allow of the lubricant
reaching the chain.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I wish it to be understood
that I am aware that various devices have before now been tried for altering the
relative speeds of two axles connected by pitch wheels and chains and that no
claim is made to the general principle of such alteration; also that I am aware that it
has before now been proposed to alter the proportion of the gearing by attaching to a
boss or centre fixed upon the crank shaft a toothed wheel either entire or made in
segments the proportion of the gearing being capable of variation according to the
size of the toothed wheel secured upon the central boss and that I make no claim to
such an arrangement. What I claim is
The combination with a chain wheel of a toothed ring such as B adapted to be fitted
upon the said chain wheel carrying upon its periphery teeth B¹ of the same character
and pitch as those of the chain wheel and formed entire or in segments substantially
as and for the purpose described and illustrated in the accompanying drawings.
Dated this Fifth dox of March 1890.
HENRY COPPINGER.
W. P. Thompson & Boult,
Agents for the Applicant.