Iμ-ПРАПОИСПО IN BANTLYDDYNN STE WATER
Year: 1870

page_text: LETTERS PATENT to Oharles Wilson and John Peebles, both of Errol,
in the County of Perth, North Britain, for the Invention of “Iμ-
ПРАПОИСКПО IN BANTLYDDYNN STE WATER"
Sealed the 22nd July 1870, and dated the 2nd April 1870.
PROVISIONAL SPECIFICATION left by the said Charles Wilson and
John Peebles at the Office of the Commissioners of Patents, with
their Petition, on the 2nd April 1870.
We, CHARLES WILSON and JOHN PEEBLES, both of Errol, in the
County of Perth, North Britain, do hereby declare the nature of the
said Invention of "IMPROVEMENTS IN EQUILIBRIUM SLIDE VALVES," to be as
follows, that is to say :-
This Invention, which has for its object a novel and effective method
of balancing slide valves, consists in the first place in supplying the
steam by one or more pipes, ducts, or passages leading from the exterior
and terminating in the valve seat and under the slide valve.
The Invention consists in the second place in forming the slide valve
with a steam duct extending from one end of the valve to the other, and
in its course passing over the exhaust cavity, by which duct the steam

page_text: is supplied to the cylinder through ports of the ordinary construction.
In order to counteract any tendency to lift the valve from the valve
seat which may be caused by the pressure of steam in the said duct a
branch is led from the exterior steam duct or passage into the valve box,
and the steam thereby supplied passes on to the top or upper surface of
the slide valve, thereby pressing it down on the valve seat and preserving
the equilibrium of the valve. The amount of steam admitted to the
upper side of the valve may be regulated by a stop-cock placed in the
branch pipe or passage, and the pressure on the upper side of the valve.
may or may not be regulated by an escape valve placed in the valve box.
In lieu of employing steam to balance the slide valve as herein-before
set forth a weight or weights may be placed on the top of the valve to
preserve the balance or equilibrium, or springs may be used for that
purpose in lieu of either of the foregoing arrangements.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Wilson and John Peebles in the Great
Seal Patent Office on the 1st October 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, CHARLES
WILSON and JOHN PEEBLES, both of Errol, in the County of Perth,
North Britain, send greeting.
: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of April, in the year
of our Lord One thousand cight hundred and seventy, in the 33rd
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said Charles Wilson and John Peebles, Her
special license that we, the said Charles Wilson and John Peebles,
our executors, administrators, and assigns, or such others as we, the
said Charles Wilson and John Peebles, our executors, administrators,
or 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 EQUILIBRIUM SLIDE VALVES,”
upon the condition (amongst others) that we, the said Charles Wilson

page_text: and John Peebles, by an instrument in writing under our 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.
NOW KNOW YE, that we, the said Charles Wilson and John Peebles,
do hereby declare the nature of 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 accom-
panying Drawings, and to the letters and figures marked thereon, that
is to say:
Our said Invention, which has for its object the balancing of slide
valves, consists in supplying the steam through one or more pipes, ducts,
or passages leading from the exterior and terminating in the valve seat
and under the slide valve. The slide valve employed is of that class
wherein one or more ducts extending from one end of the valve to the
other are used, and through which duct or ducts the steam is supplied
to the cylinder through ports or passages of the ordinary construction.
In order to counteract any tendency of the steam in the said duct to
lift the valve from the valve seat, which may be caused by its pressure
in the said duct, a branch or passage is led from the exterior steam duct
or passage into the valve chest, and the steam thereby supplied passes
on to the top or other surface of the slide valve, thereby pressing it down
on the valve seat and preserving the equilibrium of the valve. The
amount of steam admitted to the upper side of the valve is adjusted
by a stop-cock placed in the branch pipe or passage.
And in order that our said Invention may be properly understood we
now proceed more particularly to set forth the system, mode, or manner
in or under which the same is or may be used or practically carried into
effect, reference being had to the accompanying Drawings and to the
letters and figures marked thereon, that is to say:-
Figure 1 is a longitudinal section, and Figure 2 is a transverse section
on the line a, a, Figure 1, of a steam engine cylinder and its fittings
showing our improved mode of equilibrating slide valves applied thereto,
whilst Figures 3 and 4 are respectively detached plans of the cylinder_face
and slide valve face. The same letters of reference mark the same or
corresponding parts upon the different Figures on which they occur.

page_text: The valve A is situated in the interior of and cast in one piece with
an outer shell B, whereby a duct or passage O is formed extending over
the back or exhaust cavity of the valve A, and terminating at both ends
in open ports D, D, one of which communicates with a duct E leading
from the steam pipe G connected with the boiler. Between the steam 5
pipe G and the interior of the valve casing II a communication is formed
by means of a small branch pipe a, which is fixed between them and
provided with a stop-cock b. When the engine is working the steam is
admitted through the steam pipe G, thence into the duct E, and passing
onward in the direction indicated by the arrows upon Figure 1 enters the 1
duct or chamber C through the opening D, thence it issues through the
ports c and c¹ alternately, and is conducted onward to the corresponding
ends of the steam cylinder F. To prevent the pressure of the steam in
the duct or chamber C from lifting the valve or pressing it upward, a
supply of steam sufficient to balance the pressure inside tending to lift 1
the valve is admitted to the interior of the valve casing H through the
small pipe or passage a, and adjusted by means of the stop-cock b. The
steam thus admitted exerts a contrary pressure and of sufficient intensity
to maintain the valve in the condition of equilibrium.
In our Provisional Specification it is stated that an escape or safety 2
valve may be used in the valve chest or casing II, but in practice we
find such a valve unnecessary and prefer to dispense with it. In placo
however of using the small pipe a and stop-cock 6 as herein-before set
forth for admitting and regulating the steam in the casing H, steam
may be admitted by means of an opening d entering from the passage 2
E, as shown upon Figure 1, or the same result may be arrived at by
admitting the steam from the duct C through an opening e in the shell
B, as also shown at Figure 1, by either of which methods the steam
admitted into the interior of the valve casing H may be so regulated as
to maintain the required pressure outside the shell B for balancing the 3
lifting pressure at the interior thereof. The last two arrangements are
less effective than the first, as the area of the holes d and e would be
difficult to adjust so as to admit the precise quantity of steam requisite
for maintaining the valve in equilibrium which the stop-cock & in the
pipe a affords.
We are aware that the employment of the shell B so as to isolate the
slide valve A from the steam in the casing or chest H is not novel, such
an arrangement being set forth in the Specification under Letters Patent
3

page_text: granted to Richard Archibald Brooman, No. 662, A.D. 1850, and in a
Provisional Specification filed by William Edward Kochs, No. 1939,
A.D. 1866, as well as in the Specification of William Weir and George
Weir, No. 3650, A.D. 1869, and such part of the arrangements specified
we do not claim, what however we do consider novel and original;
and therefore claim as the Invention secured to us and as a means for
avoiding the complex reducing valves for producing differential pressure
is, the pipe a for admitting steam from the steam pipe G, and the cock b
for regulating the supply thereof in quantity sufficient to balance the
lifting tendency of the pressure of the steam within the shell B, also tho
admitting of steam to effect a similar result through the passages a
and e as hercin-before described and shown on the appended Sheet of
Drawings.
In witness whereof, we, the said Charles Wilson and John Peebles,
have hereunto set our hands and seals, this Twenty-fourth day of
September One thousand eight hundred and seventy.