An Im- PROVED SLIDE VALVE."
Year: 1874

page_text: LETTERS PATENT to Thomas Browning, of Commercial Road, White-
chapel, and George Joseph Scott, of Bow Common Lane, Mile End,
both in the County of Middlesex, for the Invention of "An Im-
PROVED SLIDE VALVE."
PROVISIONAL SPECIFICATION left by the said Thomas Browning.and
George Joseph Scott at the Office of the Commissioners of Patents,
with their Petition, on the 7th August 1874.
We, THOMAS BROWNING, of Commercial Road, Whitechapel, and
GEORGE JOSEPH SCOTT, of Bow Common Lane, Mile End, both in the
County of Middlesex, do hereby declare the nature of the said In-
vention for "AN IMPROVED SLIDE VALVE," to be as follows :—

page_text: The following is the manner we propose to construct slide valves
according to our said Invention:-The slide is composed of a couple of
pistons joined together by a rod or other suitable means so as to leave
space between them to establish a communication with the exhaust.
The said slide works in a small truly bored cylinder attached to the side
of the ordinary cylinder of an engine. The ports for the inlet, outlet,
and exhaust of steam communicato with the cylinder of the engine and
the small cylinder aforesaid in the usual way, motion being given to tho
slide by any suitable means. A pipe is fixed at each end of the small
cylinder, both of which communicate with the main pipe of the boiler
if steam be employed as the motive power.
1
The operation of a slide valve as above constructed is as follows:-
Supposing the motive power to be steam, the steam is admitted through
the main pipe and passes through the two pipes communicating with
both ends of the slide valve, thus causing an equal pressure on each of
the outside faces of the slide, whatever may be its position in the small
cylinder, and forming a perfect equilibrium valve, which may be adapted
to any ordinary engine.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Browning and George Joseph Scott in the
Great Scal Patent Office on the 6th February 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wе, THOMAS
BROWNING, of Commercial Road, Whitechapel, and GEORGE Joseph
SCOTT, of Bow Common Lane, Mile End, both in the County of Mid-
llesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of August, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Thomas Browning and Georgo
Joseph Scott, Her special licence that we, the said Thomas Browning
and George Joseph Scott, our executors, administrators, and assigns, or

page_text: such others as we, the said Thomas Browning and George Joseph Scott,
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, tho
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED SLIDE
VALVE," upon the condition (amongst others) that we, the said Thomas
Browning and George Joseph Scott, our executors or administrators,
by an instrument in writing under our or their, or one of their hands and
seals, 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 montlis next and immediately after the date of the said Letters

page_text: both ends of the slide valve, thus causing an equal pressure on each of
the outside faces of the slide, whatever may be its position in the small
oylinder, and forming a perfect equilibrium valve, which may be adapted
to any ordinary engine.
And in order to explain our said Invention moro fully we will now {
procced to describe the means by which it may be carried into practical
effect, reference being had to the illustrative Drawing accompanying
theso Presents, and to the letters of reference marked thereon, as
follows:-
The Drawing represents a sectional clevation of our improved slide
valve attached to an ordinary cylinder. A is part of the cylinder with
the ports B, B'; and exhaust C. D is a small cylinder attached to the
side of the cylinder A, and communicating therewith by the openiigs b, b¹,
and c. Inside this cylinder is a valve E, which is formed of the two 1
pistons e, e¹, furnished with packings, and connected together by the
part e". The valve E is adjusted on the rod F by means of tho
nuts ƒ,ƒ³‚ƒ", ful. The rod F passes through the stuffing boxes G, G³,
and receive motion from an eccentric or other means. The steam enters
at both ends of the slide valve D, as shown by the arrows, by means 2
of the pipes H, H³, which are connected with the boiler by an inlet
pipe K.
The operation of a slide valve constructed as above will be as follows:-
Supposing the valve E to be moved upwards, the steam would enter at
the bottom port B¹ of the main cylinder and force the piston up, by 2
which time the small cylinder e will have uncovered the port B of the
main cylinder a to allow the steam to enter the cylinder at that port and
force the piston down, and the steam that was underneath the said piston
will pass through the port B₁ between the small pistons e, e¹, into the
exhaust C. The two outer surfaces of the pistons e, e', marked 1, 11, 3
being exactly the same, it is evident that the pressure on both surfaces
will be the same at all times, thus constituting an equilibrium valve.
Having now described and set forth the nature and object of our said
Invention for "An Improved Slide Valve," and the means whereby it

page_text: may be carried into practical effect, we would remark in conclusion that
what we claim as our Invention and desire to secure by tho hercin-before
in part recited Letters Patent is, constructing equilibrium slide valves,
substantially as described and represented.
In witness whereof, we, the said Thomas Browning and George
Joseph Scott, have hereunto set our hands and seals, this Sixth
day of February, in the year of our Lord One thousand eight
hundred and seventy-five.
THOS. BROWNING.
(L.S.)
GEORGE JOSEPH SCOTT. (L.S.)