IMPROVEMENTS IN STEAM ENGINES
Year: 1868

page_text: LETTERS PATENT to Thomas Lester, of Wordesley, in the County of
Stafford, Engineer, and William Trucman, of Lays Foundry, Brier-
ley Hill, in the County of Stafford, Iron Founder, for the Invention
Sealed the 12th February 1869, and dated the 31st August 1868,
PROVISIONAL SPECIFICATION left by the said Thomas Lester and
William Trueman at the Office of the Commissioners of Patents,
with their Petition, on the 31st August 1868.
We, THOMAS LESTER, of Wordesley, in the County of Stafford, Engi-
neer, and WILLIAM TRUEMAN, of Lays Foundry, Brierley Hill, in the
County of Stafford, Ironfounder, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN STEAM ENGINES," to be as follows:-
Our Invention consists, firstly, of the following improvements in
working the slide valves of steam engines. This part of our Inven-
tion consists of an improvement on a portion of the Invention for
which Letters Patent were granted to Thomas Lester (one of the present

page_text: applicants) on the 21st day of January, 1865, No. 183. In the Speci-
fication of the said Patent there is described (among other matters)
an arrangement for working the slide valves of steam engines, consist-
ing essentially of the following parts:-The end of the slide valve rod
is formed into a ring, within which ring the crank shaft of the en-
gine works. On the top and bottom of this ring studs are made
against which cams or tappets on the crank shaft, and situated on
opposite sides of the ring, are made alternately to act, one cam or
tappet acting on one stud and effecting the advance motion of the
slide valve rod, and the other cam or tappet acting on the other stud
at the opposite end of the ring, and effecting the return motion of
the slide valve rod. In place of the fixed studs, against which the
cams or tappets work as described, we use moveable surfaces in the
form of antifriction rollers. By the use of antifriction rollers a
smoother action is obtained and greatly diminished wear results. By
this improvement the steam may be cut off at any part of the stroke
required.
Our Invention consists, secondly, of the following improvement or
improvements in condensing steam engines. This part of our Inven-
tion has for its object the rapid and uniform removal of the waste
or condensed steam from the condenser, thereby forming a more
perfect vacuum on the vacuum side of the piston than has hitherto
been produced. This we effect by connecting with the condenser
two pumps worked by excentrics on the main shaft of the engine.
We so arrange these pumps that while one is making its advance
stroke the other is making its return stroke. The waste steam and
air thus drawn from the condenser pass by pipes connected with the
pump cylinders into the atmosphere; or the waste steam may be
utilized. The condenser to which our Invention is applied is furnished
with the ordinary injection apparatus. By the use of the pumps
described the condenser is rapidly and uniformly cleared of the waste
steam from the steam cylinder, and a very perfect vacuum thereby
obtained on the vacuum side of the piston. This part of our Invention
is especially applicable to high-pressure condinsing steam engines.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Lester and William Trueman in the
Great Seal Patent Office on the 24th February 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
LESTER, of Wordesley, in the County of Stafford, Engineer, and WILLIAM
TRUEMAN, of Lays Foundry, Brierley Hill, in the County of Stafford,
Ironfounder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of August, in the year
of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Thomas Lester and William Trueman,
Her special licence that we, the said Thomas Lester and William True-
man, our executors, administrators, and assigns, or such others as we,
the said Thomas Lester and William Trueman, our 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 STEAM
ENGINES," upon the condition (amongst others) that we, the said Thomas
Lester and William Trueman, our executors or administrators, by an
instrument in writing under our or their hands and seals, or under the
hand and seal of one of us or them, 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 Letter Patent.
NOW KNOW YE, that I, the said Thomas Lester, on behalf of my-
self and the said William Trueman, do hereby declare the nature of
the said Invention, and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following state-
ment thereof, that is to say:-
Our Invention consists, firstly, of the following improvement in working
the slide valves of steam engines. This part of our Invention consists'
of an improvement on a portion of the Invention for which Letters
Patent were granted to Thomas. Lester (one of the present Patentees)

page_text: on the 21st day of January 1865, No. 183. In the Specification of the
said Patent there is described (among other matters) an arrangement
for working the slide valves of steam engines consisting essentially of
the following parts -The end of the slide valve rod is formed into a
ring, within which ring the crank shaft of the engine works. On the
top and bottom of this ring studs are made against which cams
or tappets on the crank shaft, and situated on opposite sides of the
ring, are made alternately to act, one cam or tappet acting on one stud
and effecting the advance motion of the slide valve rod and the other
cam or tappet acting on the other stud at the opposite end of the ring
and effecting the return motion of the slide valve rod. In place of the
fixed studs against which the cams or tappets work as described, we
use moveable surfaces in the form of antifriction rollers.
By the
use of antifriction rollers a smoother action is obtained and greatly
diminished wear results.
This part of our Invention is illustrated in Figures 1, 2, and 3 of the
accompanying Drawing, Figure 1 being an end elevation, Figure 2 a
front elevation, and Figure 3 an end clevation of the crank shaft of the
engine and one of the cams or tappets..
a is the crank shaft of the engine, and b, b', are the cams or tappets
fixed thereon; c is the slide valve rod of the engine, the upper end of
which is formed into a ring d in which the crank shaft a works as
represented. At the top and bottom and on opposite sides of the ring d
are antifriction rollers e, f. By the rotation of the crank shaft a of the
engine the cams or tappets b, b', are made to act alternately on the
rollers e, f, and to communicate a reciprocating motion to the slide
valve rod c and thus work the slide valve, that is to say, the cam or
tappet acting on the roller f effects the advance motion of the slide
valve rod c and the other cam or tappet bacting on the roller e effects
the return motion of the slide valve rod c as will be understood by an
examination of Figure 2, where the position of the cams or tappets b, b',
on the shaft a is best seen. By this improvement the steam may be cut
off at any part of the stroke required.
Our Invention consists, secondly, of the following improvement or
improvements in condensing steam engines. This part of our Invention
has for its object the rapid and uniform removal of the waste or condensed
steam from the condenser, thereby forming a more perfect vacuum on

page_text: the vacuum side of the piston than has heretofore been accomplished.
This we effect by connecting with the condenser two pumps worked by
excentrics on the main shaft of the engine. We so arrange these
pumps that while one is making its advance stroke the other is making
its return stroke. The waste steam and air thus drawn from the con-
denser pass by pipes connected with the pump cylinders into the
atmosphere. This part of our Invention is illustrated in elevation and
section in Figure 4 of the Drawing, g is the condenser and h, i, are the
two pumps connected therewith; k is the cylinder of the condensing
engine communicating with the condenser g. The said pumps h, i, are
arranged to work alternately by means of excentrics on the shaft of the
engine, that is while the pump h is making its advance stroke the pump i
is making its return stroke, and the reverse. The waste steam and air
drawn from the condenser g by the action of the pumps h, i, pass by
the pipes m, n, of the pump cylinders into the atmosphere or elsewhere.
The pumps h, i, are of the ordinary construction. By the use of the
pumps described and represented, the condenser is rapidly and uniformly
cleared of the waste steam from the steam cylinder and a very perfect
vacuum thereby obtained on the vacuum side of the piston. In order
to effect the perfect condensation of the waste steam entering the
condenser g from the cylinder k, we arrange the injection apparatus
in the following manner :-The waste steam from the cylinder enters the
perforated tube fixed in the condenser. Between the said tube / and
the condenser g is an annular chamber p and outside the said chamber is
an annular belt q communicating with the said chamber p. The belt q
is perforated with a series of small holes and is connected with the
pipe conveying. the injection water. By this arrangement of the
injection apparatus the injection water from the annular belt q is pro-
jected in the form of a series of fine jets against the upper part of the
pipe 1, whereby the said pipe is kept uniformly cold and the steam
entering the said pipe is rapidly condensed. This part of our Invention
is especially applicable to high pressure condensing steam engines.
Having now described the nature of our Invention and the manner in
which the same is to be performed, we wish it to be understood that we
do not limit ourselves to the precise details herein described and illustrated
as the same may be varied without departing from the nature of our
Invention; but we claim as our Invention of improvements in steam
engines,―

page_text: Firstly. The arrangement or combination of parts herein-before
described and illustrated in Figures 1, 2, and 3 of the accompanying
Drawing for working the slide valves of steam engines.
Secondly. The use of two pumps arranged and worked in the manner
herein-before described and illustrated in the accompanying Drawing
for rapidly and uniformly clearing the condensers of condensing engines
of waste or condensed steam and air.
Also the arrangement of the parts of the injection apparatus of
condensing engines herein-before described and illustrated in the accom-
panying Drawing.
In witness whereof, I, the said Thomas Lester, have hereunto
set my hand and seal, this Twenty-second day of February,
in the year of our Lord One thousand eight hundred and sixty-
nine.
Witness,
GEORGE SHAW.
THOMAS LESTER. (L.S.)