Improvements in Driving Chains for Bicycles, Tricycles, and other Purposes.
Year: 1889

page_text: Date of Application, 2nd Dec., 1889-Accepted, 4th Jan., 1890
COMPLETE SPECIFICATION.
Improvements in Driving Chains for Bicycles, Tricycles, and other
Purposes.
I CHARLES HENRY BRAMPTON of 14 Oliver Street Birmingham in the County
of Warwick Manufacturer do hereby declare the nature of my said invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
My invention has for its object improvements in driving chains for bicycles
Tricycles and other purposes and is for the purpose of giving a larger or more useful
life to such chains whether they be used for vehicles such as velocipedes or for the
driving of machinery of any kind though they are specially applicable to the driving of
velocipedes. At present when driving chains have been worn to a considerable extent the
usefulness is greatly impared because not only is the length of the chain increased by
the wear at the joints but the pitch of each link is perceptably increased so that even
after the chain is tightened by the removal of one or more links there is a distinct
and constant tendency for the chain to ride upon every tooth of the wheels as they
present themselves and the result is continuous jerks which are both disagreeable and
dangerous to the rider and greatly detrimental to the machine. There are also other
disadvantages inherent to such a state of things. The present mode of dealing with
this trouble is to tighten the chain by increasing the length between the centre of the
wheels or by the removal of one or more links or by renewing the chain. Now my
invention is intended to prevent the need of renewals in a great measure if not entirely
by supplying a chain which will move nearly approximate in its own life to that of
the machine itself so that when a machine is sold with my new chain the owner will
be able by the ordinary facilities he possesses to always keep the chain in good
working condition. Chains as at present made have their holes or joint pins
concentric with the links or driving blocks so that both sides are practically
alike.
In order that my invention may be clearly understood and more easily carried into
practice I have appended hereunto a double sized sheet of drawings upon which I
have illustrated my invention as applied to two different types of chains and which
will enable others to apply the principle to other kinds of chains to which my inven-
tion may be applicable but I do not confine myself by any means to the two examples
shewn neither do I claim the principles of the construction of the chains shewn as
both are well known types now in the market.
Figure 1 shews the driving block A of a chain as now used perhaps more widely
than any other type of chain and also the addition of my improvement thereto of
the extra metal a¹ with the sectional lines running in the contra direction to those of
the old portion A.
Figure 2 is an enlarged longitudinal sectional elevation through the centre of the
chain on line F H Figure 4.
Figure 3 is a side elevation of the same chain as in the case of the previous
figure.
Figure 4 is a plan shewing both side links B as well as the driving blocks A.
Figure 5 is an elevation of a chain wheel E with the A side of the chain in wear on
next to the wheel on the left side thereof and the a' side of the chain next to the
wheel on the right hand side thereof.
Figure 6 is a plan of the second type of chain now in the market in which the
driving blocks care one piece with the links c which gives a less number of joints in
any given chain.
Figure 7 is a sectional side elevation on M. N. shewing the extra thickness of the
metal c³ on one side thereof but it is shewn more clearly by the supplemental section

page_text: Figure 11 where the extra metal is shewn by sectional lines running in an opposite
direction as in Figure 1.
Figure 8 is a side elevation of the same chain as that shewn in section by
Figure 7.
t
Figure 9 shews the pivot pin for the second type of chain but my invention makes
no difference to that portion.
Figure 10 is a view shewing the side link c with its solid block c¹ forged or made
thereon which is likewise not new except in regard to the extra thickness piece c²
which I am about more fully to explain.
Now taking the first or more ordinary type of chain as illustrated by Figures 1-5
there is the A side of the chain which is the ordinary size as now used and the a¹ side
which constitutes my present invention. In all cases the ordinary side would be
first applied when the chain is new as seen at the left side of Figure 5 and would be
run on that side until the chain had been elongated say about two per cent. more or
less according to construction or desire of the owner. During this time the pins K
would be worn to a perfect bearing in the links and the pitch of the chain which
exactly corresponded with the teeth of the wheel E to commence with would now be
found to be longer and therefore would lie upon the wheel very loosely and would
work with more or less tendency to ride upon the teeth to shake and to jerk in
working. Now while the chain has been working on its A side the centre line
of its working diameter upon the wheel E has been that represented by dotted
lines R. The chain is now simply reversed thus bringing my new side a¹ next to
the wheel as seen at the right hand of Figure 5 when the working diameter centre
line is represented by the dotted lines S which is larger in diameter than R by the
difference in two thicknesses of the extra metal a¹ as seen at Figure 1 in the first type
of chain or the extra metal c² as seen at Fig. 11 in the second type of chain. Thus
the parts a² of the blocks when worked inwardly as on the right side of Fig. 5 are
brought nearer together on account of their greater distance from the centres K and
the effective pitch of the chain is thus practically reduced. An approximation of the
above result may be made by the addition of a little metal such as shewn by a³
Figure 12 but it will only be an approximation because the configuration of the
two sides of the driving block A would be different and therefore would not fit the
wheel as effectively as in the case of Figures 1 and 11.
The driving blocks c¹ may be made quite round as seen at Figure 13 so as to allow
a friction roller or ring c³ to turn thereon. Also the driving blocks A may be made
in a number of thicknesses or plates as shewn by Figure 14 say four, more or less.
The enlargement a' on block A may sometimes only leave its extra thickness as shewn
at Figure 15 in which case the block is lighter by cutting more metal out of the hollow
of the second side as seen at a*.
A similar effect to the extra metal a¹ is produced by drilling the links eccen-
trically as seen at Figure 16 where the driving block A is exactly the size of A
Figure 1.
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 :-
First. The improvements in driving chains for Bicycles Tricycles, and other
purposes of the addition to the driving blocks A or C of the extra formation a¹ or c²
substantially as and for the purpose herein set forth.
Second. The improvements in driving chains for bicycles Tricycles and other
purposes of chains having holes or pivots placed eccentrically such as shewn by
Figures 13 and 16 substantially as herein set forth.
Dated this 30th day of November 1889.
GEORGE BARKER.
77, Colmore Row, Birmingham, Agent for Applicant.