IMPROVEMENTS IN APPARATUS FOR ASCERTAINING AND INDICATING THE DUTY' OF STEAM ENGINES, MODIFICATIONS OF THE SAID APPARATUS BEING ALSO APPLICABLE TO OTHER PURPOSES
Year: 1869

page_text: LETTERS PATENT to William Ashton, of Manchester, in the County
of Lancaster, and John Henry Storey, of the same Place, Engineers,
for the Invention of "IMPROVEMENTS IN APPARATUS FOR ASCERTAINING
AND INDICATING THE DUTY' OF STEAM ENGINES, MODIFICATIONS OF THE SAID
APPARATUS BEING ALSO APPLICABLE TO OTHER PURPOSES."
Sealed the 30th July 1869, and dated the 10th April 1869.
PROVISIONAL SPECIFICATION left by the said William Ashton and
John Henry Storey at the Office of the Commissioners of Patents,
with their Petition, on the 10th April 1869.
We, WILLIAM ASHTON, of Manchester, in the County of Lancaster,
and JOHN HENRY STOREY, of the same Place, Engineers, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN APPARATUS
FOR ASCERTAINING AND INDICATING THE DUTY' OF STEAM ENGINES, MODIFICATIONS
OF THE SAID APPARATUS BEING ALSO APPLICABLE TO OTHER PURPOSES," to be as
follows:-
Our Invention relates to apparatus employed to ascertain with more
or less of exactness the amount of force or power exerted by steam

page_text: engines in a given time or otherwise to ascertain the effective duty of
the said engines.
When employing an ordinary "indicator" for the above purpose
indications have been taken at intervals during the working of the
engine, and the said indications have constituted the bases of calcula-
tions to ascertain the duty of the engine, any fluctuations in the
amount of power exerted by the said engine which may have occurred
between two consecutive indications not effecting the result of the said
calculations.
When employing the apparatus constructed in accordance with our
Invention the force exerted during each stroke of the piston is measured
with more or less of exactness and is registered, a dial attached to the
apparatus furnishing means for the ascertainment of the total amount
of force exerted during any suitable interval of time, the general
arrangement of the said apparatus being as follows:-A comparatively
small cylinder is fitted with a piston, and is connected with the cylinder
of the steam engine in such a manner as that the said piston shall be
acted upon by the pressure of the steam or by the force due to the
combined action of steam and of a partial vacuum at the same times
and to the same degree in proportion to its area as the piston of the
steam engine. The piston rod of the indicator is connected with a
spiral spring which controls the action of the indicator piston, the said
spring resisting the movement of the said piston in either direction
from the position of equilibrium, which is at about the centre of the
cylinder, the spring being made about proportionate to the area of
the said piston and to the pressure acting thereon. On the aforesaid
piston rod is mounted a friction wheel or pinion to which a variable
rotatory motion is imparted during the working of the engine by a
disc, the surface of which is in contact with the circumference of the said
friction wheel. The said disc is caused to rotate alternately in opposite
directions, the said rotation being derived from the engine similarly
as in the case of the barrels of the ordinary indicators, or in any suitable
manner, the said disc rotating to a suitable extent in one direction
during the forward or upward stroke of the piston of the engine, and in
the reverse direction during the return stroke thereof. When the engine
is not in action the indicator piston remains at about the centre of its
cylinder and the friction wheel in contact with the centre of the driving
disc or thereabouts, the spiral spring being in equilibrium. On steam

page_text: being admitted to one side of the engine piston, and as a consequence
to the corresponding side of the indicator piston, the last-named
piston is moved in its cylinder until the force tending to move it is
balanced by the resistance of the spiral spring, the aforesaid friction
wheel being at the same time moved from the centre towards the
circumference of the driving disc, and as the said disc is rotating at a
speed proportionate to the speed of the engine piston, and as the friction
wheel is moved farther from the centre of the said disc as the pressuro
on the piston increases and nearer to the said centre as the said
pressure decreases, it follows that the speed of rotation of the friction
wheel at all times during the stroke of the engine piston will bear a
proportion to the speed of the said piston multiplied by the pressure
on the same or nearly. As during the forward stroke of the engine
piston the friction wheel is moved from the centre of the disc in one
direction, as for example, upwards, and during the return stroke is moved.
from the centre downwards, the friction wheel rotates in the same
direction during both of the said strokes, although the direction of
motion of the driving disc is reversed at each stroke. A pinion attached
to or connected with the friction wheel is in connection with a
registering or counting apparatus, the dial of which indicates the
effective duty of the engine or nearly in units or multiples of horse
power, or furnishes the basis of a calculation having for its object
to ascertain the duty of the engine in units of "horse power" or other-
wise as desired. In some cases the number of strokes or double strokes
made by the engine is also registered and indicated. In lieu of the
double-acting indicator piston above described two single-acting pistons
may be employed if preferred.
A modification of the above-described apparatus may be employed as
a dynanometer, as, for example, to ascertain the tractive force exerted
by a locomotive, and a further modification of the said apparatus may be
employed to measure the superfices of irregular figures or diagrams, the
rotating disc and friction wheel being employed in both cases.
The details of the apparatus as herein described may be variously
modified, as, for example, a cone may be employed in lieu of the afore-
said disc, or the said disc or cone may in some cases rotate constantly
in one direction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Ashton and John Henry Storey in the
Great Seal Patent Office on the 9th October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
ASHTON, of Manchester, in the County of Lancaster, and JOHN HENRY
STOREY, of the same Place, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of April, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said William Ashton and John Henry
Storey, Her special license that we, the said William Ashton and John
Henry Storey, our executors, administrators, and assigns, or such
others as we, the said William Ashton and John Henry Storey, our
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 "Im-
PROVEMENTS IN APPARATUS FOR ASCERTAINING AND INDICATING THE DUTY OF
STEAM ENGINES, MODIFICATIONS OF THE SAID APPARATUS BEING ALSO APPLICABLE
TO OTHER PURPOSES," upon the condition, amongst others, that we, the
said William Ashton and John Henry Storey, by an instrument in
writing under our hand and seal, should particularly describe and ascer-
tain 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 we, the said William Ashton and John Henry
Storey, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement and accompanying
Drawings, that is to say :-
Our Invention relates to apparatus employed to ascertain with more
or less of exactness the amount of force or power exerted by steam

page_text: engines in a given time, or otherwise to ascertain the effective duty of the
said engines.
When employing an ordinary "indicator" for the above purpose
indications have been taken at intervals during the working of the
engine, and the said indications have constituted the bases of calculations
effected in order to ascertain the duty of the engine, any fluctuations in
the amount of power exerted by the said engine which may have occurred
between two consecutive indications not effecting the result of the said
calculations.
When employing the apparatus constructed in accordance with our
Invention the force exerted during each stroke of the piston is measured
with more or less of exactness and is registered, a dial attached to the
apparatus furnishing means for the ascertainment of the total amount of
force exerted during any suitable interval of time, the general arrange-
ment of the said apparatus being as follows:-A comparatively small
cylinder is fitted with a piston and is connected with the cylinder of the
steam engine in such a manner as that the said piston shall be acted
upon by the pressure of the steam or by the force due to the continued
action of steam and of a partial vacuum at the same times and to the
same degree in proportion to its area as the piston of the steam engine.
The piston rod of the indicator is connected with a spiral spring, which
controls the action of the indicator piston, the said spring resisting the
movement of the said piston in either direction from the position of
equilibrium, which is at about the centre of the cylinder, the spring being
made about proportionate to the area of the said piston and to the
pressure acting thereon. On the aforesaid piston rod is mounted a
friction wheel or pinion to which a variable rotary motion is imparted
during the working of the engine by a disc, the surface of which is in
contact with the circumference of the said friction wheel. The said disc
is caused to rotate alternately in opposite directions, the said rotation
being derived from the engine similarly as in the case of the barrel of
the ordinary indicator or in any suitable manner, the said disc rotating
to a suitable extent in one direction during the forward or upward stroke
of the piston of the engine and in the reverse direction during the return
stroke thereof. When the engine is not in action the indicator piston
remains at about the centre of its cylinder, and the friction wheel in
contact with the centre of the driving disc or thereabouts, the spiral
spring being in equilibrium. On steam being admitted to one side of

page_text: the engine piston, and as a consequence to the corresponding side of the
indicator piston, the last-named piston is moved in its cylinder until the
force tending to move it is balanced by the resistance of the spiral spring,
the aforesaid friction wheel being at the same time moved from the
centro towards the circumference of the driving disc, and as the said disc
is rotating at a speed proportionate to the speed of the engine piston, and
as the friction wheel is moved farther from the centre of the said disc
as the pressure on the piston increases and nearer to the said centre as
the said pressure decreases, it follows that the speed of rotation of the
friction wheel at all times during the stroke of the engine piston will
bear a proportion to the speed of the said piston multiplied by the
pressure on the same or nearly. As during the forward stroke of
the engine piston the friction wheel is moved from the centre of the disc
in one direction, as, for example, upwards, and during the return stroke
is moved from the centre downwards, the friction wheel rotates in the
same direction during both of the said strokes, although the direction of
motion of the driving disc is reversed at each stroke. A pinion attached
to or connected with the friction wheel is in connection with a registering
or counting apparatus, the dial of which indicates the effective duty of
the engine or nearly in units or multiples of horse power, or furnishes
the basis of a calculation having for its object to ascertain the duty
of the engine in units of horse power or otherwise as desired.
In some
cases the number of strokes or double strokes made by the engine
is also registered and indicated. In lieu of the double-acting indicator
piston above described single-acting pistons may be employed if
preferred.
The details of the apparatus as herein described may be variously
modified, as, for example, a cone may be employed in lieu of the
aforesaid disc, or the said disc or cone may in some cases rotate
constantly in one direction.
In order that the said Invention may be fully understood we have
annexed to this Specification a Sheet of Drawings having letters of
reference marked thereupon, similar letters indicating corresponding
parts in the various Figures.
Referring to the said Drawings Fig. 1 is a sectional elevation of one
form of the apparatus, Fig. 2 is a front view thereof; Fig. 3 is a cross
section on the line A, B, and Fig. 4 a cross section on the line C, D, in
Fig. 1; and Fig. 5 is a side elevation of the upper portion of the apparatus

page_text: with a portion of the outer case removed to shew the interior; the said
Figures being drawn about one-half the full size.
In the said Figures a is a small steam cylinder, which is fitted with a
piston b. The space above the piston is connected by means of the
pipe c with one end of the engine cylinder, and the space below the
said piston is connected by means of the pipe with the other end of
the engine cylinder, so that there may be as nearly as possible the same
force per square inch acting on the piston a as on the engine piston.
The pipes c and d are fitted with stop-cocks or valves e, e, and with "pet-
cocks" x, x. The piston rod fis continued upwards through the cover a',
and the bearing 9 and the upper end thereof is attached to the spiral
spring h, the said spring offering an increasing resistance to the motion
of the piston in either direction from the central position, as shewn in
the Drawing. On the said piston rod is mounted a friction pinion i,
which is attached to the long pinion j, and is free to revolve on the said
rod. On the shaft k, which is fitted to revolve in suitable bearings, is
fixed or formed the flat circular disc 1, and also the band pulley m,
which receives a rotatory motion from the engine by means of cords n, n,
for which purpose one of the said cords may be connected with the
piston rod cross head, or with some other portion of the engine moving
at the same speed as the engine piston, or at a speed proportionate
thereto, the other cord being attached to a spring or to a weight; or
the said cords may be joined into an endless band and connected with a
moving portion of the engine as aforesaid; or other arrangements for
giving motion to the disc may be adopted, it being requisite in this
example that when the engine piston is making a forward or upward
stroke the disc shall revolve in one direction, as, for example, in the
direction indicated by the black arrow, and when the said piston is
making a backward or downward stroke the said disc shall revolve in
the contrary direction indicated by the dotted arrow. The disc is kept
in contact with the friction wheel i by means of the spring o. Supposing
the engine cylinder to be vertical, and the upper end thereof to be con-
nected with the upper end of the cylinder a, the action of the apparatus
will be as follows:-On steam being admitted to the upper end of
the engine cylinder the piston 6 will move downwards to an extent
determined by the pressure of the steam, and in the case of condensing
engines to the tension of the vacuum on the under side of the piston.
This movement of the piston will cause the friction wheel i to move

page_text: downwards from the centre of the disc towards its circumference, and
as the engine piston moves downwards the said disc will be caused to
revolve, say, in the direction of the dotted arrow, and will impart a
revolving motion to the friction wheel and to the pinion j in the
direction indicated, and as the friction wheel will at all times during
the stroke of the engine piston move farther from or nearer to the
centre of the disc as the moving force acting on the said piston increases
or decreases, and as the revolution of the disc is proportionate to the
movement of the piston, it follows that the extent of the revolution of
the friction wheel will be in proportion to the force exerted by the
engine during the said stroke, disregarding friction and slight causes
of error. During the upward stroke of the engine piston the friction
wheel will be moved upwards from the centre of the disc, and as the
said disc will then be revolving in the direction of the black arrow the
said friction wheel will continue to revolve in the.direction indicated.
The pinion gears with the wheel p fixed on the vertical spindle ",
a worm on the upper end of the spindle gearing with a worm
wheel 8, which is fixed on the same arbor as the unit index . The
units indicated by the said index may be either units of horse power
exerted by the engine, or each unit may represent a number of foot
pounds for each square or circular inch of the engine piston's area, or
each unit may bear any other desired proportion to the duty of the
engine according as may be desired.
For general purposes we have found it convenient to so proportion the
gearing between the friction wheel and the index that each unit shall
represent 10,000 foot pounds on each circular inch of the engine piston.
The method of registering the number of revolutions of the friction wheel
may be considerably modified without departing from the main principle
of action of the apparatus. The smaller indices register the duty of the
engine to the higher places of figures, as will be well understood. The
apparatus may also be employed to furnish a diagram on paper similar
to the ordinary indicator diagram. For this purpose a cylinder to hold
the paper, shewn by dotted lines in Fig. 5, is mounted on the bracket t,
and is capable of revolving on a central spindle as is usual, being
actuated in any ordinary manner, or by means of a cord attached to the
boss of the pulley m, as shewn. The pencil or tracing point is shewn
at t', and is attached to the piston rod f. By closing the lower tap a
diagram of the down stroke may be taken, and by closing the upper tap

page_text: and opening the lower one a diagram of the up stroke may be taken
without having to move the apparatus. The index y, Fig. 2, receives
motion from the spindle through a train of gearing, which is so pro-
portioned with reference to the area of the steam engine cylinder as that
the number of divisions passed by the said index during one minute will
indicate the horse power exerted, as, for example, one revolution made
by the index shewn in the Drawing, supposing the dial to be correctly
marked, would indicate a duty of twenty horse power. The remaining
Figures, drawn about quarter size, illustrate some of the modifications
which may be made in the apparatus.
In Fig. 6 the piston rod of the indicator is connected to the sliding
rod f' by the lever u and the links ut. In this example the movement of
the rod f¹ is much greater than that of the piston, and the area of the
said piston is proportionately increased, this arrangement being of
advantage in some cases.
In Fig. 7 two single-acting pistons are employed working in cylinders
a², a², fixed to each end of the main cylinder and connected together
by the rod f. This arrangement is designed to shorten the steam
passages. In this example a different arrangement of the indices &* is
shewn.
In Fig. 8 the cylinder a³ is connected with the steam passages of the
engine cylinder by means of the passages and taps e, e, and the piston
rod passes through both ends of the cylinder, being connected by one
end to the spring h, and by the other end to the long pinion j, which
slides on a fixed stud w and carries the friction wheel i.
In some cases a cone may be substituted for the disc 1, being applied
in a similar manner, as shewn by the dotted lines at vin Fig. 1, and
being rotated by the engine as in the case of the disc, but this arrange-
ment is not conveniently applicable to double-acting engines.
Having now fully described our said Invention, we wish it to be
understood that we do not confine ourselves to the precise details as
herein described and as illustrated in the accompanying Drawings, nor
do we claim the employment of our apparatus, or of any modification
thereof, as a dynamometer or for measuring the superfices of irregular
figures, notwithstanding anything to the contrary contained in our
Provisional Specification; but that we claim, the employment for the
purpose or purposes herein set forth of any of the forms of apparatus
herein described and illustrated in the Drawings herein referred to, or of

page_text: any modification of the said apparatus, in which a friction wheel or
pinion, as, for example, the wheel i, is moved in the direction of its axis
by steam pressure derived from the engine cylinder or from the steam
passage or passages leading from the valve or valves to the said
cylinder.
In witness whereof, we, the said William Ashton and John Henry
Storey, have hereunto set our hands and seals, this Eighth day
of October, in the year of our Lord One thousand eight hundred
and sixty-nine.
Signed and sealed by the said
William Ashton and John
Henry Storey in the pre-
sence of
EDWARD K. DUTTON,
Agent to the Patenteos,
3, Smithy Door,
Manchester.
WILLIAM ASHTON.
(L.S.)
JOHN HENRY STOREY. (L.S.)