IMPROVEMENTS IN VALVES OF STEAM ENGINES
Year: 1871

page_text: LETTERS PATENT to James Petrie, of Rochdale, in the County of
Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN VALVES
OF STEAM ENGINES."
Sealed the 19th April 1872, and dated the 21st October 1871.
PROVISIONAL SPECIFICATION left by the said James Petric at the
Office of the Commissioners of Patents, with his Petition, on the
21st October 1871.
I, JAMES PETRIE, of Rochdale, in the County of Lancaster, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN VALVES OF STEAM ENGINES," to be as follows :-
My Invention consists, firstly, in an arrangement whereby the stop
valve and throttle valve become enclosed in one casing. For this
purpose I employ a pipe, one end of which is provided with a seating
for the stop valve, the rod by which it is worked extending through a
bonnet fitted to the said pipe. At the other end of the pipe is a chamber
which contains a rotatory valve, to be worked by any suitable connection

page_text: with the governor, the axis of the said valve being at right angles to the
axis of the stop valve.
Secondly, in a peculiar construction of throttle valve I employ there
is a rotating tube formed with openings (wedge formed by preference),
and moving in a case also provided with openings. These two parts are
enclosed by a casing to which steam is admitted, and from thence it
passes into the interior of the valve, thereby pressing equally upon its
surface in all directions. When the openings in the two surfaces are
brought more or less coincident by the governor, steam is allowed to pass
in like proportion to the engine. The outer casing is furnished with
suitable bonnets to admit of access to the valves.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Petric in the Great Seal Patent Office on
the 19th April 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
PETRIE, of Rochdale, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of October, One
thousand eight hundred and seventy-one, and in the thirty-fifth
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said James Petric, Her special license that
I, the said James Petrie, my executors, administrators, and assigns,
or such others as I, the said James Petric, my executors, adminis-
trators, 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 VALVES OF
STEAM ENGINES," upon the condition, amongst others, that I, the said
James Petrie, 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 Scal Patent Office within six

page_text: PackV.
NOW KNOW YE, that I, the said James Petric, 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:-
In the accompanying Drawing my Invention is shown in vertical
section at Fig. 1, and at Fig. 2 is a similar section taken at right angles
thereto; Fig. 3 is a section in plan, taken about the line A, B, of Fig. 2.
At a is a casing provided with a flange b, by which it may be united to
the steam pipe proceeding from the boiler. Within the casing a is a
pipe c, provided at its upper end with a scating d, upon which is fitted
the stop valve e of ordinary construction, and the rod of which passes
through a stuffing box f, carried by a bonnet g attached to the upper
part of the casing a. The lower part of the tube c is bushed at h, and
around the circumference of this bush is formed a series of apertures i
(Fig. 2), which I prefer to form transversely, as seen by dotted lines at a*.
Within the bush is a cylinder k, open at each end and having around
its circumference a series of apertures j, corresponding to those shewn at
i in the bush h. The cylinder & although open at each end has arms 7,
provided with bosses which are mounted fast upon a shaft m, one end of
which turns in a bonnet n carried by the casing a, and the other in a
bearing formed in another bonnet o, and through which the said shaft
passes, its outward end being attached to a lever p, which is connected
to the governor of the engine. According to the position of the parts
shewn the stop valve e is closed, but when the said valve is raised by
means of the pulley handle q, steam will flow through the piper and
into the chamber 8, as shewn by the arrows, and from thence downward
so as to enter the cylinder at each end, and thus place it in equilibrium.
From the interior of this cylinder the steam flows through the apertures
j thereof, and through those marked i in the bush 7, passing out around
the whole of the circumference thereof, and thus arrives at a chamber t,
from whence it passes to the engine through a pipe u. It has been
stated that the shaft m is connected by a lever to the governor; accord-
ing therefore to the action of the said governor the cylinder k is turned
more or less upon its axis, and the apertures i, j, are more or less closed,
so as to pass a proportionate quantity of steam, as will be well understood.

page_text: A modification of my Invention is shown at Fig. 4 in a vertical section,
and at Fig. 5 in horizontal section, the difference being that in this
case the regulating valve has a vertical axis, and the stop valve a
horizontal axis. At e is the stop.valve, the rod of which passes through
a stuffing box f, carried by a bonnet g, and placed in this instance on
two scats d, d, so as to form a communication from the steam pipe r to
two chambers 8, 8*, which lead to the chamber t, in which the regulating
valve k is mounted. The spindle of this valve turns in a step / at its
lower end, its upper passing through the stuffing box m, and carrying a
lever Р which is connected to the governor. The regulating valve as
before is provided with apertures j, corresponding to those formed in the
outer stationery ring h. When the stop valve e is raised the steam flows
into the passages 8, 8*, and from thence into the circular space t, so as
to surround the valve, which is thus in equilibrium. From thence the
steam passes, in this instance, through the openings i, j, into the interior
of the valve, and to the engine through the pipe u.
Having thus described and ascertained the nature of my said Inven-
tion, and the manner in which the same is to be performed, I desire it
to be understood that I claim as secured to me under the above in part
recited Letters Patent,-
Firstly, in reference to the employment of a rotary regulating valve,
enclosing it in the same casing which contains the stop valve, and placing
the axes of the said valves at right angles to each other.
Also the construction and arrangement of regulating valve above
described.
1
In witness whercof, I, the said James Petrie, have hereunto set
my hand and scal, this Sixteenth day of April, in the year of
our Lord One thousand eight hundred and savants twe
JAMES PETRIE. (L.S.)