Improvements in Means or Devices for Adjusting the Driving Chains of Cycles.
Year: 1897

page_text: Date of Application, 21st June, 1897
Complete Specification Left, 21st Mar., 1898—Accepted, 21st June, 1898
Improvements in Means or Devices for Adjusting the Driving
Chains of Cycles.
We, ALEXANDER ROBERT MACBETII, and MILNERS' SAFETY CYCLE CO. LIMITED,
of Aigburth Street, Liverpool, in the County of Lancaster, Works Manager and
Cycle Manufacturers, do hereby declare the nature of this invention to be as
follows:-
This invention has for its object an arrangement for tightening and 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
operating screws which adjusted the position of the axle so as to tighten or loosen
the chain. By this arrangement however an amateur was very liable to turn the
nuts on one side of the wheel more than the other side, with the result that the
axle would be on the skew, that is to say the wheel would be liable to revolve in
a plane oblique to that of the frame.
The present invention is designed to avoid this defect and enables a rider to
ensure the axle being in alignment, that is to say at right angles to the vertical
plane of the frame.
To this end we provide on the outside face of that part of the frame which con-
nects the thrust rod with the back fork (by preference a flat plate) a rack formed
of a series of teeth or serrations of given pitch, and engaging in each of these racks
is a washer having on its face similar teeth of similar pitch so that the two sets of
teeth when pressed together shall interlock. The relative positions of the teeth
on the two plates exactly correspond, so that if one washer be made to engage
certain teeth on one plate and the other washer corresponding teeth on the other
plate, the centre holes in the two washers will be exactly and accurately in line.
The ends of the axle are passed through the slots in these two plates, the washer
slipped on the ends of the axle and locked against the racks by nuts, thus firmly
holding the axles in position. To adjust the chain all that is necessary is to
slacken the nuts sufficiently on each side to enable the washers to free themselves
from engagement with the nuts, then slide the axle horizontal in the slots until
the necessary chain adjustment is obtained, then tighten up the nuts again, care
being taken that the respective washers shall each engage the corresponding teeth
in the racks on each side. To ensure this the teeth may be numbered so that the
rider may be able to see at a glance that the washer on the two sides engages the
teeth with the corresponding numbers. Or in place of numbering the rider could
count the teeth and in that assure himself that the proper teeth were being engaged
to ensure correct alignment of the axle.
We have described the above way of carrying the invention into effect, but it
must be understood that having once given the general idea, alterations may be
made without departing from the nature of the invention. Thus for example,
the teeth or serrations may be on the inside of the plates instead of the outside

page_text: face, and the washers which interlock thereon mounted on the axle between the
plates and the wheel.
Dated this 19th day of June 1897.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicants.
Improvements in Means or Devices for Adjusting the Driving
Chains of Cycles.
We, ALEXANDER ROBERT MACBETH, and MILNERS' SAFETY CYCLE Co. LIMITED,
of Aigburth Street, Liverpool, in the County of Lancaster, Works Manager and
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 has for its object an arrangement for tightening and 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
operating screws which adjusted the position of the axle so as to tighten or loosen
the chain. By this arrangement however an amateur was very liable to turn the
nuts on one side of the wheel more than the other side, with the result that the
axle would be on the skew, that is to say the wheel would be liable to revolve in
a plane oblique to that of the frame
The present invention is designed to avoid this defect and enables a rider to
ensure the axle being in alignment, that is to say at right angles to the vertical
plane of the frame.
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 a bicycle;
Figure 2 a front view;
Figure 3 a detail view of the washer.
:
We provide on the outside faces A of that part of the frame which connects the
thrust rod with the back fork (by preference a flat plate) a rack B formed of a
series of teeth or serrations of given pitch, and engaging in each of these racks is
a washer C having on its face similar teeth of similar pitch so that the two sets of
teeth when pressed together shall interlock. The relative positions of the teeth B
on the two plates A A exactly correspond, so that if one washer C be made to
engage certain teeth on one plate, and the other washer corresponding teeth on
the other plate, the centre holes in the two washers will be exactly and accurately
in line. The ends D of the axle are passed through the slots E in these two plates,
the washers C slipped on the ends of the axle and locked against the racks by
nuts F, thus firmly holding the axles in position. G is the nave of the wheel to
which the spokes are attached, H the chain wheel. To adjust the chain all that
is necessary is to slacken the nuts F sufficiently on each side to enable the
washers C to free themselyes from engagement with the rack, then slide the axle
horizontally in the slots until the necessary chain adjustment is obtained, then
tighten up the nuts again, care being taken that the respective washers shall each
engage the corresponding teeth in the racks on each side. To ensure this, the
teeth may be numbered so that the rider may be able to see at a glance that the
washer on the two sides engages the teeth with the corresponding numbers. Or

page_text: in place of numbering, the rider could count the teeth and in that assure himself
that the proper teeth were being engaged to ensure correct alignment of the axle.
We have described the above way of carrying the invention into effect, but it
must be understood that having once given the general idea, alterations may be
made without departing from the nature of the invention. Thus for example,
the teeth or serrations may be on the inside of the plates instead of the outside
face, and the washers which interlock thereon mounted on the axle between the
plates and the wheel. Also the washer C may be made circular and provided with
a shank I with a nut i screwed on the end thereof and a cross plate J for the nut
to bear against, see Figures 2 and 3. By screwing up the nuts i therefore and
slacking the nuts F, the axle can be adjusted to tighten the chain.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
1. In cycles, mounting on each end of the axle a washer having a series of teeth
on their inner faces, providing the outside faces of that part of the frame
immediately adjacent thereto with a series of similar teeth of similar pitch to the
teeth on the washers, and making the relative position of the teeth on the two
outside faces of that part of the frame to exactly correspond, whereby if one washer
be made to engage certain teeth on one side, and the other washer corresponding
teeth on the other side, the centre holes of the two washers will be exactly and
accurately in line, and 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 a driving wheel axle of washers, serrated
on their inner faces, racks located on the outside faces of the frame immediately
adjacent to the points through which the axle passes, and having their teeth of
similar pitch to the pitch of those on the washers, and nuts at each end of the
axle for screwing up the serrated washers so as to engage in the teeth of the
serrated racks substantially as and for the purpose described.
101
1
1. 1000
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham, and London.