IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINE INDICATORS
Year: 1886

page_text: I EDWARD MORTON of Advance Works Hollins Street Stalybridge in the County
of Chester, General Brass Finisher, do hereby declare the nature of my invention
for IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINE INDICATORS and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to the construction of indicators for ascertaining and
recording the power and quality of work performed by steam engines, and
especially to that class of indicators known as, " Richards Indicators" wherein the
cylinder, carrying the paper upon which the indication or diagram is to be recorded,
is caused to oscillite to and fro by means of a cord attached to a convenient moving
part of the steam engine and a spring reacting in the reverse direction, whilst the
pencil or marker is attached to a light parallel link motion in connection with a
piston acted upon by the steam.
The object of my invention is to simplify the construction of the detent
arrangement employed in such indicators for locking the cylinder which holds the
paper to the grooved pulley to which the cord is attached and unlocking the same
when required.
The nature of my said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference to
the accompanying drawings and the following explanation thereof.
Fig. 1, on the annexed drawings is a front elevation (drawn partly in section) of
so much of a "Richards Indicator" as is necessary to illustrate my invention.
Fig. 2. is a side elevation of the same showing the detent arrangement in the locked
position and Fig. 3 is a similar view showing the same unlocked.
a, a is the light cylinder, to which the paper is attached, which is removable but
fits closely on the cylinder b, b being connected thereto by a slot and pin at c, c as
usual. d, d is the spring box and e, e is the grooved pulley to which the cord from
the engine is attached.
It is well understood that the paper cylinder a, a is only required to oscillate at
such time as the indication is actually being taken and that at other times the
grooved pulley must be free to oscillate with the movement of the cord without
imparting any motion to the cylinder a, a.

page_text: For this purpose the flange bx, of the cylinder b, b is made with a notch f, f in
which slides a bolt g, g attached to a locking pin or detent h, h. This bolt is acted
upon by a spring i, i (Fig. 1) which has a constant tendency to depress the locking
più or detent h, h so as to force the head of, the said pin to enter a hole in the
upper side of the grooved pulley e, e and thus lock the cylinder and pulley together.
Sliding vertically through a hole in the frame or base k k of the apparatus is a
second bolt, provided with a spring m, m (stronger than the spring i, i) which
has a constant tendency to lift the bolt 1, 1; and it will be evident that, if there
were nothing to counteract it, each time the bolt g, g (in oscillating with the
cylinder) passed the bolt 2, the latter would raise the foriner so as to release the
detent h, h and unlock the cylinder b, b from the grooved pulley e, e; and at
the same time the upper end of the bolt 1, would enter the notch f, f in the
flange b* of the said cylinder and hold it firmly so as to prevent it from oscillating
with the grooved pulley as shown at Fig. 2.
In order however to prevent this detent arrangement from acting whilst the
indication is being taken the bolt 1, Z is held down by means of a lever n, n (as
shown at Fig. 3) the said lever being pressed side-ways into a notch o, o Fig. 1. by
means of a spring P, P.
When it is desired to release the cylinder b, b from the grooved pulley all that
is necessary is to press the lever n, n sideways out of the notch and allow the
bolt, to rise, which on the next oscillation will release the locking pin or
detent h, h and at the same time lock the cylinder fast by entering the notch in
the flange bx.
When the paper cylinder is required to oscillate so as to take the indication the
attendant depresses the lever n, n and the spring p, p presses it sideways into the
notch o, o thus holding the bolt 1, 7 down out of the way.
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. The improved detent arrangement for steam engine indicators constructed
and operating substantially as hereinbefore described and illustrated by the
drawings annexed and
r
Secondly. I claim the combination with the locking bolt or detent h, h of the
vertical sliding bolt 1, with its spring m, m lever n, n and notch o, o constructed
and arranged substantially in the manner and for the purposes hereinbefore
set forth.