Improved Driving Gear for Bicycles.
Year: 1897

page_text: Date of Application, 14th Dec., 1897
Complete Specification Left, 20th Jan., 1898-Accepted, 5th Mar.,
1898
Improved Driving Gear for Bicycles.
We, ROBERT PEACOCK and GEORGE ALBERT BEETLESTONE, both of 13, High
Road, Kilburn, London, N.W., Cycle Manufacturers, do hereby declare the nature
of this invention to be as follows:
_
This invention relates to improved driving gear for bicycles, particularly
tandems, and has for its object to lessen the disadvantage of high gear in hill
climbing by enabling increased power to be then obtained whilst retaining the
advantages of such gear for running on the level, the gear being so proportioned as to
gear both down and up.
According to this invention as applied to a tandem the two pedal axes are geared
together by chain and equal sprocket wheels and the rearmost pedal axis is geared
with the driving wheel of the machine through intermediate gear consisting of a
sprocket wheel on the opposite end of the rear pedal axis to, and preferably of the
same number of teeth as the sprocket wheel on which the front chain runs this
second sprocket wheel being geared by a short chain with a sprocket wheel having
a larger number of teeth on an intermediate axis mounted preferably in front of the
rear bottom bracket and upon which is a sprocket wheel having a still larger
number of teeth by which the requisite high gear is obtained and which is geared
by a chain with the pinion on the hub of the driving wheel of the machine the
preferred ratio of the intermediate gear being such that the pedal axle will make
about one-and-a-half revolutions to one of the large sprocket wheel instead of an
equal number of revolutions as when the two turn together as one.
Dated this 14th day of December 1897
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
We, ROBERT PEACOCK and GEORGE ALBERT BEETLESTONE, both of 13, High
Road, Kilburn, London, N.W., Cycle Manufacturers, 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:
This invention relates to improved driving gear for bicycles, particularly
tandemis or multicycles and has for its object to lessen the disadvantage in hill
climbing of a long-continued and exhausting muscular effort at each down stroke
of the pedal and the longer dwell on the dead point incidental to the slow revolu-
077
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page_text: tion of the pedal axis when a very high gear is used between the pedal axis and the
driving wheel. This end is accomplished by a combination of gearing which en-
ables increased power to be obtained under such circumstances whilst retaining
the advantages of a high gear for running on the level, the gearing being so com-
bined and proportioned as to first gear "down" and then "up" as hereafter des-
cribed and illustrated in the accompanying drawing forming part of this Specifica-
tion which represents in Figure 1 a side elevation and in Figure 2 a plan of the
framing, and chain gearing of a tandem bicycle, the gearing being represented in
Figure 1 by the pitch lines only.
According to this invention as applied to a tandem the two pedal. axes A A¹ are
geared together by chain B and equal sprocket wheels CC and the rearmost
pedal axis A is geared with the driving wheel D of the machine through inter-
mediate gearing consisting of a sprocket wheel E on the opposite end of the rear pedal
axis to that at which the sprocket wheel C is situate. This second sprocket wheel E
has preferably the same number of teeth as the wheel C and is geared by a short
chain F with a sprocket wheel G having a larger number of teeth than the wheel E
and fast on an intermediate axis H mounted in a bearing I on the lower member
of the machine frame in front of the bracket in which the pedal axis A is mounted.
Fast upon the opposite end of the intermediate axis H is another sprocket wheel K
having a still larger number of teeth by which the requisite high gear is obtained,
this wheel K being geared by a chain L with the pinion M on the hub of the
driving wheel D of the machine. The preferred ratio of the gearing is such that
the pedals will make about one-and-a-half revolutions to one revolution of the
large sprocket wheel K instead of an equal number of revolutions as when the two
turn together as one. This result is obtained by giving, for example, to each of
the wheels CCE sixteen teeth, to the wheel G twenty-four teeth, to the wheel K
thirty-eight teeth, and to the pinion M eight teeth, but it is to be understood that
the invention is in no way confined to this particular number of teeth but
may be varied so long as the combination of down" and "
up
described is retained.
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39
gear as herein
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
In a bicycle the herein described combination of intermediate gear operating
substantially as described for the transmission of motion from the pedal axle to the
driving wheel.
Dated
this 20th day of January 1898
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.