IMPROVED APPARATUS FOR REGISTERING THE SPEED OF ENGINES AND OTHER MACHINERY
Year: 1858

page_text: LETTERS PATENT to Alexander Mitchell, of Glasgow, Machinist, for the
Invention of "IMPROVED APPARATUS FOR REGISTERING THE SPEED OF ENGINES
AND OTHER MACHINERY."
Sealed the 31st May 1859, and dated the 18th December 1858.
PROVISIONAL SPECIFICATION left by the said Alexander Mitchell at
the Office of the Commissioners of Patents, with his Petition, on the
18th December 1858.
I, ALEXANDER MITCHELL, of Glasgow, Machinist, do hereby declare the
nature of the said Invention for "IMPROVED APPARATUS FOR REGISTERING THE
SPEED OF ENGINES AND OTHER MACHINERY," to be as follows:-
The chief object of this Invention is to note the number of strokes made by an
engine in any given time, and thus, by affording a reliable record of the
performance of factory, steamboat, and other engines during any given period,
to shew the manner in which the engineer has attended to his duties. This.I
effect by employing a clock or timekeeper in connection with the counter of
the engine (which counter may be of any ordinary construction), so that a
band or drum of ruled paper driven by the engine and carried along by the
counter will indicate by the amount of its traverse the number of strokes
made by the engine, while a style or other marking or printing apparatus,
brought into action by the clock or timekeeper at given moments, will divide
the gross number of strokes and indicate on the paper the intervals of time
between which these strokes were performed.
The Invention it will be understood is applicable also to the noting of the
velocities of fans, rotary pumps, and other machinery.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Mitchell in the Great Seal Patent Office on the
18th June 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MITCHELL, of Glasgow, Machinist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of December, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Alexander Mitchell, .Her special license that I, the said Alexander
Mitchell, my executors, administrators, and assigns, or such others as I, the
said Alexander Mitchell, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVED
APPARATUS FOR REGISTERING THE SPEED OF ENGINES AND OTHER MACHINERY," upon
the condition (amongst others) that I, the said Alexander Mitchell, by an
instrument in writing under my hand and seal, should particularly describe
and ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Alexander Mitchell, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
My Invention relates to a mode of obtaining a record of the performance
of engines and other machinery during any given divisions of time embraced
within a given period. This object I propose to effect, in the case of an
engine, for example, by noting with a style or other marking instrument upon
suitably prepared paper the number of strokes which it has made in a given
time, using for this purpose the motive power derived from a clock or time-
keeper in combination with motive power derived from the engine whose
performance it is desired to record. The way in which this combination of
motive agency is to be applied may be varied, that is to say, the prepared
paper may be carried under the style or marker by power derived from the

page_text: engine and the style or marker operated by the timekeeper, or vice versâ, as
thought most convenient. In the arrangement of counting and recording
apparatus shewn in the accompanying Drawing, I propose to use the clock-
work for driving the drum which carries the paper, and to take the power for
setting the style or marker in action from the machine or engine whose
.performance is to be recorded.
Fig. 1 is a front view, shewing the clock and index face; Fig. 2 is a sectional
plan, shewing the counting and recording apparatus; and Fig. 3 is a side
elevation of the same. A is a drum or cylinder, carrying on its periphery a
coating of paper or other suitable material, ruled so as to divide the markings
of the style a according to the periods of time (whether of hours, days, weeks,
months, or years) during which they were made. On the axle of the drum A
is keyed a spur wheel A', which receives motion by any suitable means from.
the works of the clock B. For rendering the gross amount of the recorded duty
of the engine or machine visible to the engineer or attendant, I provide an
index or counter C, of any ordinary construction, which I connect to the
engine or machine whose duty is to be registered through the agency of the
lever D; this lever is mounted loosely on an axle E, which is carried by
suitable bracket bearings. To the axle is keyed a ratchet wheel e, into the
teeth of which a click on the lever D takes for the purpose of driving it, and
on the same axle is a worm f, which gears into a worm wheel g, attached to the
pinion of the first dial of the index. As, therefore, the lever D is caused to
vibrate by reason of its connection with the engine or machine under test, the
ratchet wheel e is driven round, and with it the worm f, which taking into the
worm wheel imparts motion to the index or counter C. The style or marker
a is carried by a spring arm attached to a travelling socket F, which is made
to slide freely over a guide bar lying parallel to the axle of the drum A. The
socket F is tapped to receive a screw shaft H, which is mounted in suitable
fixed bearings, and receives motion from the spur wheel A', through the spur
wheel I, which it carries. By thus mounting the style or marker a, a slow
traverse motion is imparted thereto, corresponding to the speed of rotation of
the drum and the breadth of the divisions on the paper covering.
To set the style or marker in operation, I adopt the following arrange-
ment: On the axle of the worm wheel g a cam excentric h is mounted, and
bearing upon the periphery is a friction roller i, which is carried by an arm k
projecting from a rocking frame K, mounted immediately in the rear of the
course of the style or marker. As, therefore, the smaller radius of the cam
or excentric is presented to the roller i, the roller will fall and cause the frame
to rock and press the style or marker into contact with the covering of the

page_text: drum, whereby a mark will be made on the paper for every movement indicated
on the counter.
:
From the foregoing explanation it will be understood that the drum travelling
at a constant rate by reason of its connection with the clock will indicate
periods of time by its revolutions, and the pointer marking the covering of the
drum at the completion of a given number of strokes or revolutions of the
machine or engine in connection with the apparatus, the duty of such engine or
machine will be correctly indicated and recorded. One revolution of the drum may
be made to record several days' work, but at every revolution it causes the screw
shaft to revolve by means of the spur gearing, and by so doing carries the
'marker a along the face of the drum, so that one cover on the drum may be
made to record months or even years of working. The duty performed may
be recorded on strips or endless bands of paper or other material, and by means
of chemical or mechanical printing, if thought desirable. I would also remark,
that when the speed of the engine or machine whose performance is to be
recorded is great, its motion must be transmitted to the index and recording
apparatus through gearing that will reduce the speed.
This Invention it will be understood is particularly applicable to sea-going
steamers, as the duty performed by the engines during the whole course of the
voyage may be seen at a glance, and the time estimated during which their
action was suspended.
Having now set forth the nature of my Invention of "Improved Apparatus
for Registering the Speed of Engines and other Machinery," and explained
the manner of carrying the same into effect, I wish it to be understood that
under the above in part recited Letters Patent I claim, combining the regulated
movement of a timekeeper with the variable motion of the engine or machine
whose performance is required to be recorded in the manner and for the
purpose herein described.
In witness whereof, I, the said Alexander Mitchell, have hereunto set
my hand and seal, the (16th) Sixteenth day of June, in the year of
our Lord One thousand eight hundred and fifty-nine.
ALEX. MITCHELL. (L.S.)