CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1853

page_text: LETTERS PATENT to William Beardmore, of Deptford, in the
County of Kent, Engineer, and William Rigby, of Glasgow, in
the County of Lanark, in Scotland, Engineer, for the Invention of
TY BA Dwarving "
Sealed the 16th January 1854, and dated the 11th October 1858.
PROVISIONAL SPECIFICATION left by the said William Beardmore
and William Rigby at the Office of the Commissioners of Patents,
with their Petition, on the 11th October 1853.
We, WILLIAM BEARDMORE and WILLIAM RIGBY, do hereby declare
the nature of the said Invention for "CERTAIN IMPROVEMENTS IN STEAM
ENGINES" to be as follows:-
This Invention consists in working the air pump with a trunk or hollow
plunger, which is connected to the steam piston by means of two or
more piston rods, which trunk is to be sufficiently large to admit of the
vibration of the connecting rod, which is connected to the crank on the
screw or other shaft at the one end, and to the further end of the trunk
plunger at the other end.
For the better guidance of the plunger and attached piston rods, we
prefer to prolong the same of a diminished diameter so as to work
through both ends of the air pump; that is, the end next the shaft
works through an opening of large diameter, whilst the other end

page_text: works through a smaller opening suited to its diminished diameter, the
<lifference between which openings will constitute the effective area of
the air pump plunger. The piston rods are connected to the end of
the plunger nearest to them, the said plunger thus forming an efficient
guide to such rods. The connecting rod passes into the hollow
plunger, and is secured therciu; and the said plunger forms a guide for
the angular thrust of same., Or instead of diminishing the size of the
plunger at one end, we can make it of the same diameter throughout,
with an annular piston outside, so as to constitute a double acting air
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Beardmore and William Rigby in the
Great Seal Patent Office on the 7th April 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we,
WILLIAM BEARDMORE, of Deptford, in the County of Kent, Engineer,
and WILLIAM RIGBY, of Glasgow, in the County of Lanark, in Scot-
land, Engincer, send greeting.
WHEREAS Fler most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of October, in the year
of our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reigu, did, for Herself, Her heirs and successors,
give and grant unto us, the said William Beardmore and William
Rigby, Her special licence that we, the said William Beardmore and
William Rigby, our executors, administrators, and assigns, or such
others as we, the said William Beardmore and William Rigby, 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,
the Channel Islands, and Isle of Man, an Invention for "CERTAIN
IMPROVEMENTS IN STEAM ENGINES," upon the condition, amongst others,
that we, the said William Beardmore and William Rigby, by an
instrument in writing under our hands and seals, or under the hand
and seal of one of us, should particularly describe and ascertain the

page_text: 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 wo, the said William Beardmore and
William Rigby, do hereby declare the nature of our said Invention,
and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:
.
The nature of our said Invention, which has reference to improve-
ments in that class of engines which may be termed "air pump trunk
engines," does, as already stated in the Provisional Specification filed
on the said Eleventh day of October One thousand eight hundred and
fifty-three, consist in working the air pump with a trunk or hollow
phunger, which is connected to the steam piston, which plunger for the
better guidance thereof, and the attached piston rods, we prolong so as
to work through both ends of the air pump, and such prolonged part of
the plunger may be of diminished diameter, so that the end next the
shaft may work through an opening of large diameter, whilst the other
works up or through a smaller opening suited to its diminished diameter.
The piston rods are connected to the end of the plunger nearest to
them, the said plunger thus forming an efficient guide to such rods.
The connecting rod passes into the hollow plunger, and is secured
therein, and the said plunger forms a guide for the angular thrust of the
samic. Or instead of diminishing the size of the plunger at one end,
we can make it of the same diameter throughout, with an annular
piston outside, the other arrangements being the same as described.
And for the better exemplification of the said Invention we will
now proceed fully to describe and ascertain the nature of our said
Invention, and in what manner the same is to be performed, referring
to the illustrative Drawings hereto annexed, and herein-after referred
to, by the words, figures, and letters following, that is to say:
DESCRIPTION OF THE DRAWINGS.

page_text: Drawing No. 2, a longitudinal vertical section of this engine with
the plunger of the same diameter throughout, with an annular piston
outside, and so arranged as to constitute a double acting air pump.
Drawing No. 3, a longitudinal vertical section of this engine, with
the plunger of the same diameter throughout, with the annular piston
outside at the end nearest the cylinder, being another form of single
acting air pump engine.
In Drawing No. 1, A denotes the cylinder; B, the piston; C, C,
piston rods; d, d, d, d, framing; e, the crank axle; f, connecting rod;
g, large part of trunk; H, small part of trunk, which is shewn as a
hollow cylindrical body, but might be solid; J, J, condenser; K, delivery
valve opening; K, L, foot valve opening; m, the air pump, barrel, or
chamber.'
In Drawing No. 2, A, cylinder; B. piston; C, C, piston rods;
d, d, d, d, framing; e, the crank axle; f, connecting rod; y,, trunk;
h, annular ring or piston of air pump; J, J, condenser; k, k, delivery
valve openings; k, l, foot valve openings; m, the air pump, barrel, or
chamber.
In Drawing No. 3, A, cylinder; B, piston; C, C, piston rods ;
d, d, d, d, framing; e, crank axle; f, connecting rod; y, trunk; h, the
air pump, piston, or larger end of trunk; J, J, condenser; k, delivery
valve openings; k, l, foot valve openings; m, the air pump, barrel, or
chamber.
By the use as aforesaid of a hollow trunk of unequal diameter pass-
ing and extending itself through the air pump, discharge valve
chambers and stuffing boxes, as shewn in Fig. 1, (where g is the large
part of said trunk, and H the small part thereof,) the said hollow
trunk to which the connecting rod and the piston rods are attached
is correctly and securely guided during the strokes of the engine. The
packings and joints of connecting rods easily secured from outside; and
the difference between the diameters of the trunk forming a simple and
efficient single acting air pump. But, instead of this, the prolongation
of the tube might be made solid, as in the manner of the ordinary air
pump rod, in which case it would still serve the purpose of a guide.
It will be seen at Drawing No. 2, that the trunk may be carried
through the air pump of equal diameter, and have attached to the

page_text: middle of it an annular ring or air pump piston (see h, Drawing No. 2,)
in which case the air pump will be double acting, the other arrange-
ments being as before described.
In Drawing No. 3, it will be seen that we can make the air pump
chamber open at the one end nearest to the cylinder, the trunk still being
carried through the stuffing box at the other end, with the annular
ring or piston, such as that adopted in Drawing No. 2, placed at the
end nearest the cylinder, (see h, Drawing No. 8,) and being made
tight, in the manner of an ordinary air pump, bucket, or piston, the
connecting rod being attached, it would vibrate in the air pump
chamber.
Having now described the nature of the said Invention, and in what
manner the saine is to be performed, we further declare that we do not
claim the adoption of an air pump plunger working in connection with
the piston, when such plunger works through one end of the air pump
chamber only; but what we claim as our Invention is, the adoption of
an air pump plunger in connection with the piston, which plunger
works through both ends of the air pump chamber, and forms an
efficient and suitable guide for the angular thrust of the connecting
rod.
In witness whereof, I, the said William Beardmore, have hereunto
set my hand and seal, this Fourth day of April, in the year of
our Lord One thousand eight hundred and fifty-four.
5 Signed and sealed in my presence,
W. BEARDMORE. (L.S.)
F. W. CAMPIN.