IMPROVEMENTS IN INDICATORS FOR STEAM ENGINES
Year: 1870

page_text: LETTERS PATENT to Thomas Williamson, of Stalybridge, in the
County of Lancaster, Brass Founder and Finisher, for the Invention
of "IMPROVEMENTS IN INDICATORS FOR STEAM ENGINES."
Sealed the 2nd May 1871, and dated the 16th November 1870.
PROVISIONAL SPECIFICATION left by the said Thomas Williamson
at the Office of the Commissioners of Patents, with his Petition,
on the 16th November 1870.
I, THOMAS WILLIAMSON, of Stalybridge, in the County of Lancaster,
Brass Founder and Finisher, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN INDICATORS FOR STEAM ENGINES," to be as
follows:-
My Invention relates to arrangements for carrying the pencil that
marks the diagram upon the paper fastened upon the moving barrel
which is placed concentric with the steam cylinder of the indicator, and

page_text: it consists in forming a cross head upon the end of the piston rod with
guides in it for a piece bent at a right angle; one arm of this piece
slides horizontally in the cross head guide, the other arm carries the
pencil, and it slides up and down with the piston rod through a guide
carried by slides arranged to move horizontally in guides secured to the
upper part of the steam cylinder. By this arrangement the movement
of the piston is transmitted directly to the pencil without any of the
ordinary objectionable joints, and the pencil can be brought to and from
the paper on the barrel with the greatest facility by a handle upon the
horizontal slides or by a small shaft and racks and pinions.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Williamson in the Great Seal Patent
Office on the 5th May 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WILLIAMSON, of Stalybridge, in the County of Lancaster, Brass Founder
and Finisher, send greeting.
'
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of November, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas Williamson, Her special license
that I, the said Thomas Williamson, my executors, administrators, and
assigns, or such others as I, tho said Thomas Williamson, 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 " IMPROVEMENTS IN
INDICATORS FOR STEAM ENGINES," upon the condition (amongst others) that
I, the said Thomas Williamson, 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.

page_text: NOW KNOW YE, that I, the said Thomas Williamson, do hereby
declare the nature of my 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):
My Invention relates to an arrangement for carrying the pencil that
marks the diagram upon the paper fastened upon the moving barrel
which is placed concentric with the steam cylinder of the indicator, and
it consists in forming a cross head upon the end of the piston rod with
guides in it for a piece bent at a right angle, one arm of which piece
slides freely in the cross head at a right angle to the piston rod, and the
other arm carries the pencil and slides freely up and down with the
piston through a guide carried by slides arranged to move horizontally
(at a right angle to the piston rod) in guides secured to the upper part
of the steam cylinder. By this arrangement the movement of the
piston is transmitted directly to the pencil without any of the ordinary
objectionable joints, and the pencil can be brought to and from the
paper on the moving barrel in a direct line with the greatest facility by
a handle upon the horizontal slides.
Fig. 1 of the accompanying Drawings is a side view, and Fig. 2 is an
end view of my improved indicator.
a is the moving barrel which surrounds and is concentric with the
steam cylinder of the indicator; 6 is the piston rod of the indicator, to
which the cross head guide c is secured by a screw c¹, which accurately fits
and rotates freely in the socket of the cross head guide (c) without moving
endways; d is the pièce bent at a right angle, one arm fitting accurately
and sliding freely through the cross head guide c, the other arm, which
is parallel to the piston rod, fitting accurately and sliding freely through
a guide e. The end of the bent piece (d) has a socket (d') at a right
angle to it to hold the pencil. The guide e is mounted on a cross
bar e', which has a slide secured to it at each end, these slides f being
parallel to each other, and they accurately fit and slide freely through
guides g secured in the cap of the steam cylinder of the indicator, and
they are connected by a bar f¹ to keep them parallel. The pencil is
moved to and from the paper or barrel (a) by the handle h secured to
the cross bar e' as shown.
I have now particularly described the nature of my Invention, and
the mode of carrying it into effect, and claim as my Invention, the

page_text: arrangement of pencil holder and mode of actuating it substantially as
berein-before described and illustrated by the Drawings.
In witness whereof, I, the said Thomas Williamson, have here-
unto set my hand and seal, this Second day of May, in the year
of our Lord One thousand eight hundred and seventy-one.