IMPROVEMENTS IN DIRECT ACTING STEAM ENGINE INDICATORS
Year: 1870

page_text: LETTERS PATENT to John Addy Hopkinson and Joseph Hopkinson,
junior, both of Huddersfield, in the County of York, Engineers,
for the Invention of "IMPROVEMENTS IN DIRECT ACTING STEAM ENGINE
INDICATORS"
Sealed the 6th September 1870, and dated the 11th March 1870.
PROVISIONAL SPECIFICATION left by the said John Addy Hopkinson
and Joseph Hopkinson at the Office of the Commissioners of
Patents, with their Petition, on the 11th March 1870.
We, JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, junior, both
of Huddersfield, in the County of York, Engineers, do hereby declare
the nature of the said Invention for " IMPROVEMENTS IN DIRECT ACTING
STEAM ENGINE INDICATORS," to be as follows :—
Our Invention relates to improvements on direct acting indicators,
such as that described in the Specification of a Patent granted to us,
and bearing date the 31st of March 1869, No. 977, and consists in
the first place in substituting for the drop guiding rod passing through

page_text: the swivel guiding arm a vertical rod or pillar fixed to any convenient
part on the upper side of the said guiding arm, such rod passing
through or outside the swivel arm to which the pencil is connected so
as to admit of the pencil being guided and applied to the paper by
working the guiding arm as required.
And our Invention consists in the second place in imparting the
required motion to the pencil by dispensing with the swivel arm
arrangement and making either the small piston rod and piston to turn
together, or the piston rod to swivel separately with the pencil arm
fixed thereon, a groove being formed in the piston rod and a correspond-
ing tongue on the guiding arm to work in such groove.
required working connection between the piston rod and the guiding
arm may be formed by making the piston rod of a square, oval, or
other suitable section and making a suitably shaped hole or collar in or
on the guiding arm.
Or the
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Addy Hopkinson and Joseph Hopkinson in
the Great Seal Patent Office on the 9th September 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
ADDY HOPKINSON and Josepí Hopkinson, junior, both of Huddersfield,
in the County of York, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of March, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said John Addy Hopkinson and Joseph
Hopkinson Her special licence that we, the said John Addy Hopkinson
and Joseph Hopkinson, our executors, administrators, and assigns, or
such others as we, the said John Addy Hopkinson and Joseph
Hopkinson, 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 "IMPROVEMENTS IN DIRECT ACTING STEAM ENGINE INDICATORS," upon the

page_text: condition (amongst others) that we, the said John Addy Hopkinson
and Joseph Hopkinson, our executors or administrators, by an instru-
ment in writing under our, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said In-
vention, 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 John Addy Hopkinson and Joseph
Hopkinson, 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, reference being had
to the Drawings hereunto annexed, and to the letters and figures
marked thereon (that is to say) :—
Our Invention of "Improvements in Direct Acting Steam Engine
Indicators" relates to improvements on direct acting indicators, such as
that described in the Specification of a Patent granted to us and bearing
date the Thirty-first day of March One thousand eight hundred and sixty-
nine, No. 977, and consists in the first place in substituting for the drop
guiding rod passing through the swivel arm a vertical rod or pillar fixed
to any convenient part on the upper side of the said guiding arm, such
rod passing through or outside the swivel arm to which the pencil is
connected so as to admit of the pencil being guided and applied to the
paper by working the guiding arm as required.
And our Invention consists in the second place in imparting the
required motion to the pencil by dispensing with the swivel arm
arrangement and making either the small piston rod and piston to turn
together, or the piston. rod to swivel separately with the pencil arm
fixed thereon, a groove being formed in the piston rod and a correspond-
ing tongue on the guiding arm to work in such groove.
required working connection between the piston rod and the guiding
arm may be formed by making the piston rod of a square, oval, or other
suitable section, and making a suitably shaped hole or collar in or on
the guiding arm.
Or the
Having thus stated the nature of the said Invention, I will proceed
o describe more particularly in what manner the same is to be performed
by reference to the accompanying Drawings and the following description
hereof.

page_text: Fig. 1 represents an indicator with an arrangement for guiding the
pencil and applying it to the paper on the barrel as required by means
of a vertical rod or pillar P fixed on the upper side of the guiding
arm D. This pillar P is firmly fixed on the guiding arm D so as to 5
stand perpendicularly thereon, and it passes through a suitable hole or
slot in the swivel arm C. By means of this arrangement and connection
of the parts by moving the guiding arm D the swivel arm C carrying
the pencil E may be worked so as to apply the pencil E to or remove it
from the paper on the barrel B as required. G is the piston rod.
In the arrangement shewn at Fig. 2 the guiding arm D is connected
with the piston rod G by means of a groove in the said rod and a tongue
on the arm, or this connection may be otherwise formed, so that by
moving the guiding arm D the piston rod and piston may receive a
swivel motion adapted to apply the pencil E to the paper on the barrel
B or remove it therefrom as required.
Figures 3 and 4 shew an arrangement for giving to the piston rod a
swivel motion as actuated by the guiding arm in Figures 2, 6, and 7.
Fig. 5 shews an arrangement with the piston and piston rod working
separately. For this purpose the upper part of the rod G is made with
a groove of square, oval, or other suitable shape, and on the requisite
swivel motion being given to the said part of the rod G by means of the
guiding arm D the pencil will be applied to or removed from the paper
as before.
Figures 6 and 7 shew in elevation and plan on an enlarged scale the
connection between the guiding arm D and the piston rod G.
Having thus described the nature of the said Invention, and in what
manner the same is to be performed, we would remark that by means
of the arrangements herein-before described several joints, slides, and
frictional parts usual in direct acting indicators are dispensed with,
whilst the weight of the pencil arm and piston rod is small compared to
the area of the piston, whereby diagrams may be taken from engines
with the greatest accuracy and facility, and we hereby declare that what
we claim as of our present Invention is, the several arrangements
herein-before described, by means of which the working or direction of a
swivel or fixed pencil arm of a direct acting indicator can be applied to
or removed from the paper on the barrel at any portion of the upwar

page_text: or downward stroke of the piston without raising or lowering the hand
of the operator.
In witness whereof, we, the said John Addy Hopkinson and Joseph
Hopkinson, have hereunto set our hands and seals, the Sixth
day of September, in the year of our Lord One thousand eight
hundred and seventy.
Witness,
JOHN JAMES ROEBUCK,
(L.S.)
JOHN ADDY HOPKINSON.
JOSEPH HOPKINSON, JUNIOR. (L.S.)
St. Peter's Street, Huddersfield,
Cashier.