IMPROVEMENTS IN ODOMETERS
Year: 1884

page_text: I, CHARLES FAIRBAIRN Mechanical Engineer of Elm Bank, Range Road
Whalley Range Manchester in the County of Lancaster do hereby declare the
nature of my invention for "IMPROVEMENTS IN ODOMETERS" to be as follows:-
-
My invention relates to improvements in instruments for measuring distances
passed over by means of a wheel or wheels on any vehicle conveyed by that
incans.
The machines of this kind are usually constructed with long trains of wheels
gearing into each other, which are complicated, liable to shake loose, and get
otherwise deranged by concussion or vibration when travelling over rough roads.
The object of this invention is to obviate this difficulty by making the Odometer
as light, and of as few pieces as possible and for this purpose, I use chiefly endless
screws driving worm wheels.
By one method of applying the Odometer the first shaft or arbor is made fast to
the axle or any suitable part of the driving wheel, so that by every revolution of
the wheel, the arbor also makes a revolution in the same time, while the Odometer
remains suspended in the same position.
By another method of fastening the Odometer to a vehicle, it remains stationery
fixed to the frame. From the shaft carrying the first worm, is suspended a
pendulum, or vibrating lever carrying a pawl, and a toothed wheel. With every
vibration of the lever the pawl moves the wheel forward one tooth. A pin on the
driving wheel moves the lever forward, and when the pin has passed, the lever falls
back to its first position ready for another movement.
I prefer using the first arrangement, the arbor carrying the first worm wheel has
on its other end a worm which engages two worm wheels of the same diameter but
One of these wheels is
one of the wheels has one tooth more than the other.
fastened on a tube, and the other on a spindle which passes through the tube
supporting it at one end, the other end rests on the tube. The arbor inside of the
tube projects through the tube at both ends, being a little longer at the back for
the purpose of allowing it to slide endways. The tube and central arbor project
through a dial at the front, and each of them carries a pointer the arbor pointer
being outside. piece of fine steel or hard brass wire is coiled round the tube
pressing against the worm wheel at one end, and the back of the dial at the other,
holds the two wheels up to the worm, and when the pointers are wanted to be put
at zero, they are pulled forward which disengages them from the worm, when they

page_text: may be put in their place, and the coiled spring again holds them in their place
when put right.
The wheel on one of the spindles may have 100 and the other 101 teeth. The
two hands make one revolution, and the difference between them at the end of it
will be one tooth, which is so arranged as to represent on the dial-one mile-and
every revolution seperates the two hands an additional tooth, so that the distance
travelled is shewn by the distance between the two hands on the dial plate, at
whatever part of the circle these may be.
The dial has two graduated circles-the outer one black, representing miles, the
inner one red, shewing furlongs and yards. The two hands are also coloured, the
red one indicating furlongs and yards.
As regards the two worm wheels driven by one worm, I use another arrangement
for indicating the number of miles travelled. Instead of using two worm wheels
working into one, worm, I use one only placed at one side of the worm, the arbor of
which, projecting through the dial plate shews furlongs and yards. A small pin is
fixed on one side of the spindle which engages a toothed wheel, moving it forward
one tooth for each revolution it makes. When it has moved a tooth forward the
spindle rests or revolves between the next two teeth, until the pin again comes
round and thus prevents the wheel from moving until the pin reaches it.
This motion is a modification of "stop" used in Geneva watches. In this case
there would be two circles, one on each side of the dial, representing miles on the
left hand, and furlongs and yards on the right.
I make the bearings for the first spindle in the Odometer as long and as large
as possible, and fastened at one end to a piece of bent steel plate, sufficiently elastic
to reduce the vibration to a minimum when travelling over rough roads. The
whole of the internal mechanism is fastened to the back of the Odometer, which
is made separate from the rest of the case, and so all the bearings can be cast on it
ready for boring and fixing, while the Odometer ought not to weigh more than
three ounces.

page_text: I, CHARLES FAIRBAIRN of Elmbank Range Road, Whalley Range Manchester,
Mechanical Engineer do hereby declare the nature of my invention for IMPROVE-
MENTS IN ODOMETERS and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:—
My Invention relates to improvements in measuring distances passed over by a
wheel or wheels, on any vehicle conveyed by that means.
The machines of this kind are usually constructed with long trains of wheels
gearing into each other, which are complicated, liable to shake loose, and get
otherways deranged, by concussion or vibration, while travelling over rough roads.
The object of this Invention is to obviate this difficulty, by making the Odometer
as light, and of as few pieces as possible, and for this purpose, I use chiefly endless
screws driving worm wheels.
By one method of applying the Odometer the first arbor is made fast to the
axle or any suitable part of the driving wheel, so that by every revolution of the
wheel, the arbor also makes a revolution in the same time, while the Odometer
remains suspended in the same position.
By another method of fastening the Odometer to a vehicle it remains stationary
fixed to the frame. From the shaft carrying the first worm is suspended a
pendulum or vibrating lever carrying a pawl and a toothed wheel
With every
vibration of the lever, the pawl moves the wheel forward one tooth. A pin on the
driving wheel moves the lever forward and when the pin has passed, the lever falls
back to its first position ready for another movement.
I prefer using the first arrangement, the arbor carrying the first worm wheel
has on its other end a worm, which engages two worm wheels of the same diameter,
but one of the wheels has one tooth more than the other. One of these wheels is
fastened on a tube, and the other on a spindle which passes through the tube,
supporting it at one end, and the other end rests on the tube. The arbor inside of
the tube projects through it at both ends, being a little longer at the back, for the
purpose of allowing it to slide endways. The tube and central arbor project
through a dial at the front, and each of them carries a pointer, the arbor pointer
being outside. A piece of fine steel, or hard brass wire is coiled round the tube,
pressing against the worm wheel at one end, and the back of the dial at the other,
holds the two wheels up to the worm, and when the pointers are wanted to be put
at zero, they are pulled forward, which disengages them from the worm, when
they may be put in their place, and the coiled spring again holds them in their
place when put right.
The wheel on one of the spindles may have 100 teeth and the other 101 teeth.
The two hands make one revolution, and the difference between them at the
end of it, will be one tooth which is so arranged as to represent on the dial
-one mile-and every revolution separates the two hands one tooth, so that the

page_text: Figure 1 is a front, and Figure 2 is a side elevation of one form of the Odometer.
A is the case containing the mechanism a, is the fixed spindle or arbor from
which the Odometer is suspended, and b is the worm working into the worm wheel c
mounted on a second arbor d. The arbor d carries on the other end a worm e,
Fig 1, working into the worn wheel ƒ On the same arbor is fixed a wheel g,
with one tooth or projection, the remainder of the periphery, being plain or smooth,
and engaging the wheel . which is moved forward one tooth by the wheel g for
every revolution the wheel g makes.
When a larger wheel h, is required to indicate a greater total distance, a pin or
tooth may be fixed in the spindle i, and the wheel / enlarged accordingly.
The arbor carrying the wheel g and the one carrying h, project through the dial
plate, and have pointers which move round the graduated circles. The right hand
circle indicates furlongs and yards, while that on the left hand of Fig 1, indicates
miles.
The Odometer is shewn in another form in Figs 3 and 4.
A is the case as above, a, the spindle from which the Odometer is suspended and
b the worm working into the worm wheel c mounted on the arbor d. It also carries
on the other end a worm e, engaging the two worm wheels f and g. The worm
wheel fis mounted on an arbor R, while the worm wheel g, is mouted on a tube i
The spindle and the tube on it, project through the dial, and each carries a pointer,
both of which travel round the dial. There is a difference of one tooth in the
number on the two wheels. If f has 50 teeth, then g has 51, or it may be f 100
and g 101. The pointers start together and for every revolution they round the
circle, the pointers become separated by an additional division of the graduated circle,
and these differences or divisions between the pointers indicate the miles travelled.
The two forms of the Odometer operate in the same manner.
The spindle a,
is
fixed to, or suspended from the hub of a wheel, while the Odometer always remains
suspended in a vertical position and thus for every position of the wheel, the arbor
or spindle a, revolves one turn inside the Odometer.

page_text: "Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed I declare that what
I claim is "
.
First. I claim the method of suspending the Odometer in connection with the
internal arrangement of worms and worm wheels, in one form of the Odometer, and
also in connection with the "stop" used in Geneva watches in the other form.
كيمم
T
100-
CHARLES FAIRBAIRN.