IMPROVED ARRANGEMENTS FOR EFFECTING AN EQUILIBRIUM OF THE STEAM PRESSURE UPON VALVES, THE SAID ARRANGE- MENTS BEING ALSO APPLICABLE FOR EFFECTING EQUILIBRIUM OF FLUID OR GASEOUS PRESSURE UPON OTHER VALVES
Year: 1862

page_text: LETTERS PATENT to Thomas Adams, of Deptford, in the County of Kent,
Engineer, for the Invention of "IMPROVED ARRANGEMENTS FOR EFFECTING
AN EQUILIBRIUM OF THE STEAM PRESSURE UPON VALVES, THE SAID ARRANGE-
MENTS BEING ALSO APPLICABLE FOR EFFECTING EQUILIBRIUM OF FLUID OR
GASEOUS PRESSURE UPON OTHER VALVES."
Sealed the 22nd August 1862, and dated the 27th February 1862.
PROVISIONAL SPECIFICATION left by the said Thomas Adams at the
Office of the Commissioners of Patents, with his Petition, on the 27th
February 1862.
I, THOMAS ADAMS, of Deptford, in the County of Kent, Engineer, do hereby
declare the nature of the said Invention for "IMPROVED ARRANGEMENTS FOR
EFFECTING AN EQUILIBRIUM OF THE STEAM PRESSURE UPON VALVES, THE SAID
ARRANGEMENTS BEING ALSO APPLICABLE FOR EFFECTING EQUILIBRIUM OF FLUID OR
GASEOUS PRESSURE UPON OTHER VALVES," to be as follows:-
The object of my Invention being that the pressure of the steam coming
from the boiler and the varying pressures that occur within the cylinder
during the distribution of the steam on the piston be caused to act equally
upon all sides of the slide or valve. The means whereby at present I intend
to effect the same are these:-I construct slide valves thus,-I make in (or
connect or adjust to) the door or front of the slide box, or in the back of the

page_text: slide itself what I term false ports (that is recesses) each of the same being
by preference (though not necessarily) opposite each of the admission ports,
and I likewise make communication ports through the said slide, such com-
munication ports being so arranged that the steam shall be allowed to pass
through the same from the cylinder to the false ports aforesaid. Although in
this description I have only mentioned steam, still these arrangements may be
applied not only to steam engines but to other engines also, and to let on and
shut off gases or fluids when desirable to use the same. And although I have
referred to slide valves only, yet my Invention is applicable to other kinds of
valves.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Adams, in the Great Seal Patent Office on tho
27th August 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
ADAMS, of Deptford, in the County of Kent, Engineer, send greeting.
our
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of February, in the year
Lord One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Adams, Her special license that I, the said Thomas Adams, my
executors, administrators, and assigns, or such others as I, the said Thomas
Adams, 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 "IMPROVED ARRANGEMENTS
FOR EFFECTING AN EQUILIBRIUM OF THE STEAM PRESSURE UPON VALVES, THE SAID
ARRANGEMENTS BEING ALSO APPLICABLE FOR EFFECTING EQUILIBRIUM OF FLUID OR
GASEOUS PRESSURE UPON OTHER VALVES," upon the condition (amongst others)
that I, the said Thomas Adams, by an instrument in writing under my band
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.
NOW KNOW YE, that I, the said Thomas Adams, do hereby declare
the nature of my said Invention, and in what manner the same is to be

page_text: 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 thereon (that is to say):
My Invention of "Improved Arrangements for Effecting an Equilibrium of
the Steam Pressure upon Valves, the said Arrangements being also applicable
for Effecting Equilibrium of Fluid or Gaseous Pressure upon other Valves,"
has for its object the production of an equilibrium of the steam, fluid, or
gaseous pressure on the valve by causing the steam, fluid, or gas to act with
equal pressure on opposite sides of the valve at the same time, thereby
obviating the loss of power caused by the unbalanced pressure on the valves
as they are ordinarily constructed and arranged. For this purpose recesses
which I term "false ports" are formed in the door or front of the slide valve
box, or in the valve in such situations as to admit of the steam, fluid,. or gas,
passing at the same time to opposite sides of the valve. There are also
passages for the steam, fluid, or gas through the valve so as to form.com-
munications between the ordinary ports leading into the cylinder,. and the
"false ports." By this arrangement the pressure on the valve of the steam,
fluid,. or gas, as it enters or. escapes from the cylinder through the ordinary
ports is balanced by the pressure of the same on the opposite part of the
valve, thereby effecting a constant equilibrium of pressures on the valve..
Having thus stated the nature of the said Invention,. 1 will proceed to
describe more particularly in what manner the same is to be performed, by.
the aid of the accompanying Drawings in which are represented slide valves
constructed in the manner above referred to.
DESCRIPTION OF THE DRAWINGS..
Fig. 1 is a plan or horizontal view of a slide valve intended to be applied
to a horizontal cylinder. Fig. 2 is a plan of the cylinder face, and Fig. 3 is
a section through the valve, valve box, and cylinder face. Figs. 4, 5, and 6.
are similar views representing a slide valve of a different construction for the
same purpose. In these several: Figures the same letters of reference indicate
corresponding parts. A, is the cylinder face; B, B, are the ports communi-
cating with the cylinder; C, is the exhaust port;, D, is the slide valve, which,
it will be seen on reference to Fig. 1, is cut out in the central part, leaving
only a kind of frame of metal, and on reference to Fig. 3, is in vertical section
in the form of a plate with the central part removed. It will also be seen
on reference to Fig. 3, that the valve fits the space between the door E of the
valve box and the cylinder face, so as not to admit of steam pressing the
valve on to the cylinder face except in the "false ports" F, F, opposite to the

page_text: ports B, B, where the pressure is balanced by that in the latter ports. G, G,
are the communications between the ordinary ports B, B, and the "false
ports F, F, through the valve. H, H, are packing plates between which
are inserted packing of india-rubber or other suitable material, in order to
give elasticity to the plates against which the valve works. It will thus be
seen on reference to Fig. 8, that the steam from the boiler will be caused to
press on the opposite ends of the valve at the same time as indicated by the
arrows, thereby producing an equilibrium of pressures on the valve in the
liorizontal direction, also that the pressure of the steam in the ports B, B,
will be balanced by that in the "false ports" F, F, the steam being free to
pass from the former to the latter, and causing an equilibrium of pressures on
the valve in the vertical direction. The exhaust also acts equally on the
inner sides of the valve.
In Figs. 4, 5, and 6 the same principle of constructing slide valves, so as
to effect an equilibrium of pressure thereon in working is shewn, but in this
case the valve is divided into two parts (which may be termed the male and
female portions of the valve) with packing inserted between them. The only
difference between this construction of valve and that above described is that
whereas in the former instance, the valve was in one piece with the packing
inserted in the door of the valve box, in the present instance the valve is
divided into two parts, with the packing inserted between them. D' is the
male portion of the valve, and D' the female portion thereof. Owing to this
mode of constructing the valve, there will be a space I all round it, in which
there will be a pressure of steam having a tendency to force the male portion D'
against the door E, and the female portion D' against the cylinder face A.
In order to balance this pressure it is necessary to form recesses K, K, both
in the door E and the cylinder face A of an area equal to that of the space
round the valve. There is a passage for steam into the recesses K formed
either in the valve or the cylinder face or the door. Should it be required to
apply pressure on the valve for the purpose of keeping it on its face, any
required amount of pressure may be applied thereto by making the recesses K, K,
less in area than the space I, round the valve.
I
The principle of constructing slide valves so as to effect an equilibrium iu
the manner above described is also applicable to valves of a cylindrical form
by making "false ports" or recesses opposite to the ordinary ports in the
shell in which the valve rotates, or in the valve itself. The communications
between the ordinary ports and the "false ports" are formed by means of a
pipe or other passage cut in the lap of the valve. I would here remark that
In all cases of applying the Invention to slide valves and other valves, the

page_text: induction passages for the steam may be changed into eduction passages, and
vice versâ, if required.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed, I hereby declare that what I claim as of my
Invention is, the construction of slide valves, and other valves in such a
manner as to effect an equilibrium of the pressures on opposite sides of the
valve both internally and externally, the equilibrium of pressure being also
maintained on the two faces of the valve by means of "false ports" and
communications between them and the ordinary ports, as herein-before described.
In witness whereof, I, the said Thomas Adams, have hereunto set my
hand and seal, this Twenty-seventh day of August, in the year of our
Lord One thousand eight hundred and sixty-two.
Witness,
WILLIAM SPENCE,
50, Chancery Lane,
Patent Agent.
THOMAS ADAMS. (L.S.)