IMPROVEMENTS IN SAFETY VALVES
Year: 1874

page_text: LETTERS PATENT to John Addy Hopkinson, and Joseph Hopkinson,
both of Huddersfield, in the County of York, Engineers, for the
Invention of "IMPROVEMENTS IN SAFETY VALVES."
Scaled the 7th May 1875, and dated the 23rd December 1874.
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 23rd December 1874.
We, JOHN ADDY HOPKINSON and Josepи HOPKINSON, both of Hud-
dersfield, in the County of York, Engineers, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN SAFETY VALVES," to be
as follows:
-
Our Invention rolates to an improved mode or method of applying
weights to externally dead weighted safety valves, that is to say, valves
weighted by weights outside the boiler, and has for its object the pre-
vention of tampering with the weights while the boiler is at work. For
this purpose our Invention consists in placing the weights inside a
suitably arranged cover or bonnet insted of outside the same as is ordi-

page_text: narily the case. This cover or bonnet may be connected to the valve by
bolts or other approved means. The said cover may be made to form
either the whole or only a portion of the weight required for the
volve
By arranging the weight internally as stated it is placed byond reach
so as to prevent tampering with it, and the cover is neat and may be
ornamental in appearance.
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 7th June 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, JoHN
ADDY HOPKINSON and JosЕPП HOPKINSON, 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 Twenty-third day of December, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
cighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said John Addy Hopkinson and Josephi
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 exccutors, 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 SAFETY VALVES," upon the condition (amongst others)
that we, the said John Addy Hopkinson and Joseph Hopkinson, our exc-
cutors or administrators, by an instrument in writing under our, or their,
or one of their hands and scals, 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 Scal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.

page_text: 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 thercon (that is to say) :-
Our Invention of "Improvements in Safety Valves," relates to an
improved mode or method of applying weights to externally dead-
weighted safety valves, that is to say, valves weighted by weights outside
the boiler; and has for its object the prevention of tampering with the
weights while the boiler is at work. For this purpose our Invention
consists in placing the weights inside a suitably arranged cover or bonnet
instead of outside the same as is ordinarily the case. This cover or
bonnet may be connected to the valve by bolts or other approved means.
The said cover may be made to form cither the whole or only a portion
of the weight required for the valve.
By arranging the weight internally as stated, it is placed beyond
reach so as to prevent tampering with it, and the cover is neat and may
be ornamental in appearance.
Such being the nature of the said Invention, we will procced to
describe more particularly in what manner the same is to be performed
by the aid of the accompanying Drawings, in which Fig. 1 is a section
of a valve constructed in the manner above referred to; Fig. 2 is a
section of a pyramid valve with the same improvements applied thereto;
and Fig. 3 is an external view of the same.
A is a suitably arranged cover or bonnet which is made to hold the
required quantity of weights B, B, for the pressure at which the valvo is
intended to blow off. This cover or bonnet is made to receive or hold
the weights inside instead of outside as is usually the case, and when
secured to the valve by means of bolts and nuts or in other suitable
manner the weights B, B, are placed beyond reach or control so long as
the boiler contains any pressure, and this arrangement is thereforc a
protection against undue interference. The said cover or bonnet A is also
a weight upon the valve, and it may be made to form all or part of the
weight required, and it enables a neat finish to be given to the appearance
of the valve.

page_text: Having thus described the nature of the said Invention and in what
manner the same is to be performed, we hereby declare that what we
claim as of our Invention is, the adaptation and application to externally
dead weighted safety valves of a cover or bonnot to hold weights as
herein-before described.
In witness whereof, we, the said John Addy Hopkinson and Joseph
Hopkinson, have hereunto set our hands and. seals, the Fourth
day of May, in the year of our Lord One thousand eight
hundred and seventy-five.
Witness,
CARTER HOYLE,
Huddersfield,
Book-keeper.
JOHN ADDY HOPKINSON. (L.S.)
JOSEPH HOPKINSON.
(L.S.)