Improvements in Means or Devices for Adjusting the Driving Chains of Cycles.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Means or Devices for Adjusting the Driving Chains
of Cycles.
I, ARTHUR FOWLER, of 27, Magdala Street, Liverpool, in the County of Lancaster,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for its object an arrangement for tightening or slackening
the driving chains of cycles. Hitherto the driving chain has usually been
adjusted by turning a nut on either side of the wheel, the turning of the nuts operat-
ing screws which adjust the position of the axle so as to tighten or loosen the
chain. By this arrangement however an amateur was very likely to turn the
nut on one side of the wheel more than the other side, with the result that the
axle will be on the skew, that is to say the wheel will be revolved in a plane
oblique to that of the frame.
The present invention is designed to avoid this defect and enables a rider to
adjust his chain, while ensuring that the driving axle shall be in alignment, that
is to say at right angles to the vertical plane of the frame and parallel with the
crank axle.
To secure this result, I provide a micrometer adjustment. The axle is mounted
at each end in a piece which slides in guides in those parts of the frame which
connect the bottom fork with the diagonal back fork. These sliding picces are
each provided with a rearwardly projecting pin each screwed with a given number
of threads per inch, and each screwed through a rotary nut mounted in a stationary
cross-piece. These nuts are secured in milled heads one on each side that can be
rotated by hand, and which have a given number of divisions on their circum-
ference, consequently a turn of both the heads through a certain number of
divisions advances the screws on each side of the wheel a relative distance. The
outside faces of those parts of the frame in which the sliding pieces moves longi-
tudinally are provided with a graduated scale, the arrangement being that one
complete turn of the milled head on each side of the wheel will advance the slides
on each side one division on the longitudinal scale, thus ensuring that the rider
when adjusting his chain, can secure the desired accuracy. The ends of the
axle are provided with nuts so that they can be locked in any required position.
To adjust the chain all that is necessary is to slacken the nuts on each end of
the axle, then rotate the milled head on each side through a certain number of
divisions, in such manner that the sliding piece on each side carrying the axlo
ends shall be advanced or retreated an equal distance. When the scale on the
one side registers exactly the same as the scale on the other side, then the rider
will know the driving wheel axle is accurately parallel with the crank axle.
1000
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.

page_text: Improvements in Means or Devices for Adjusting the Driving Chains
of Cycles.
I, ARTHUR FOWLER, of 27, Magdala Street, Liverpool, in the County of Lancaster,
Engineer, 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 has for its object an arrangement for tightening or slackening
the driving chains of cycles. Hitherto the driving chain has usually been
adjusted by turning a nut on either side of the wheel, the turning of the nuts operat-
ing screws which adjust the position of the axle so as to tighten or loosen the
chain. By this arrangement however an amateur was very likely to turn the
nut on one side of the wheel more than the other side, with the result that the
axle will be on the skew, that is to say the wheel will be revolved in a plane
oblique to that of the frame.
The present invention is designed to avoid this defect and enables a rider to
adjust his chain, while ensuring that the driving axle shall be in alignment, that
is to say at right angles to the vertical plane of the frame and parallel with the
crank axle.
To secure this result, I provide a micrometer adjustment.
The invention will be understood from the following description, reference
being had to the accompanying drawings, in which,
Figure 1 is a general perspective view of the invention applied to the back fork
of a bicycle;
Figure 2, a front elevation;
Figure 3, is a sectional plan through the micrometer adjustment.
Referring to these figures, the axle A is mounted at each end in a piece B
which slides in guides C in those parts of the frame which connect the bottom
fork D with the diagonal back fork E. These sliding pieces B are each provided
with a rearwardly projecting pin F, each screwed with a given number of threads
per inch and each screwed through a rotary nut G mounted in a stationary cross
piece H secured to C. These nuts G are secured by the set screws i in milled
heads I one on each side that can be rotated by hand and which have a given
number of divisions marked on their circumferences, consequently a turn of both
the heads through a certain number of divisions advances the screws F on each
side of the wheel a relative distance. The outside faces of those parts of the
frame in which the sliding pieces B move longitudinally, are provided with a
graduated scale J, the arrangement being that one complete turn of the milled
head I on each side of the wheel will advance the slide B on each side one division
on the longitudinal scale J, thus ensuring that the rider when adjusting his chain
can secure the desired accuracy. The ends of the axle A are provided with nuts K,
so that they can be locked in any required position.
To adjust the chain, all that is necessary is to slacken the nuts K on each side
of the axle, then rotate the milled head I on each side through a certain number
of divisions in such a manner that the sliding piece B on each side carrying the
axle ends shall be advanced or retreated an equal distance. When the scale on
the one side registers exactly the same as the scale on the other side then the
rider will know that the driving wheel axle is accurately parallel with the crank
axle. By this invention a very accurate adjustment can be obtained.

page_text: 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:
1. The improvement in means or devices for adjusting the driving chains of
cycles, which consists in dispensing with the usual nuts on the screwed pins which
adjust the position of the back wheel axle, and providing instead in connection
with the axle ends on each side of the wheel, a micrometer device adapted when
operated to so adjust the position of the axle as to tighten or loosen the chain, each
of said micrometers having a graduated scale so arranged that if the micrometer
on one side be adjusted into a given position, and the micrometer on the other
side be adjusted into a like position so that the scale on each side registers the
same, then the axle will be in exact alignment, that is to say at right angles to
the vertical plane of the frame, substantially as described.
2. In cycles, the combination with the driving wheel axle of pieces sliding
longitudinally in guides in the frame, in which pieces the ends of the axles are
mounted, in combination with micrometers with graduated scales displayed there-
on, and longitudinal graduated scales located in close proximity to where the
sliding pieces move longitudinally, the said scales being so arranged that one com-
plete turn of the milled head of the micrometer on each side of the wheel will
advance or retreat the slides on each side one division on the longitudinal scale,
whereby in adjusting the chain the greatest accuracy can be secured, substantially
as described.
3. The general combined arrangement and construction of parts forming my
improved device for tightening and slackening the driving chains of cycles, whilst
ensuring that the chain wheels shall be in alignment.
t
HITOA TANO ZIS
W. P. THOMPSON & Co.,
Patent Agents,
Of Liverpool, Manchester, Birmingham and London.