IMPROVEMENTS IN STEAM-ENGINES
Year: 1881

page_text: LETTERS PATENT to Samuel Geoghegan, of St. James' Gate Brewery, Dublin,
Ireland, and John Sturgeon, of No. 3, Westminster Chambers, Victoria Street,
London, Civil and Mechanical Engineers, for an Invention of “IMPROVEMENTS
IN STEAM-ENGINES."
PROVISIONAL SPECIFICATION left by the said Samuel Geoghegan and John
Sturgeon at the Office of the Commissioners of Patents on the 27th October
1881.
SAMUEL GEOGHEGAN, of St. James' Gate Brewery, Dublin, Ireland, and JOHN
STURGEON, of No. 3, Westminster Chambers, Victoria Street, London, Civil and
Mechanical Engineers. "IMPROVEMENTS IN STEAM ENGINES."
Our Invention has for its object improvements in steam engines, and relates,
firstly, to an improved method of heating the steam cylinder by live steam applied
internally instead of in an external jacket in the manuer hitherto usually
employed; and secondly, to an improved mode of balancing the weight of pistons
as ordinarily applied.
To carry out the first part of our Invention according to one modification, we
construct the steam cylinder about double the length required for the stroke, and
apply two steam pistons placed about the length of stroke apart on the piston rod
so as to leave a space between the two pistons, into which space the live steam is
admitted, and thereby brought into direct contact with the inner surface of the
cylinder, instead of outside as heretofore.
Thus as the double piston travels forward it carries with it a body of hot steam
warming the cylinder in advance of the incoming or expanding steam, while the
portion of the cylinder in front from which the steam is exhausting, and which
consequently does not require heating is not heated unnecessarily, as is the case in
an externally jacketed cylinder.
The steam may be admitted to the space between the two pistons through a
passage formed in the centre of the cylinder, and any condensed water may be
drained off therefrom through an aperture or passage suitably arranged for the
purpose.

page_text: According to another modification of our Invention, instead of placing the two
pistons the full length of stroke apart we arrange them only a sbort distance from
each other, and admit the steam to the space between through a hollow tail rod,
piston rod, or telescope tube passing through the cylinder cover, or by means of
other suitable contrivance.
Instead of the double piston, as described in the above modifications, a single
piston may be employed recessed in the middle so as to form an annular steam
space; or the piston may be hollowed so as to form a central steam space in the
piston, the periphery of which between the piston rings is left open, thus bringing
the steam into contact with the inner surface of the cylinder; and in this case
steam may be admitted to the interior of the piston through a valve or valves
opening inwards, or by means of a telescope tube or other suitable contrivance,
admitting the steam either direct from the cylinder itself, or from a pipe leading
from the boiler.
In applying a piston thus arranged to a horizontal engine, we drain off the
condensed water through an opening formed at or about the centre of the cylinder
and at the bottom thereof, which opening is closed by a valve loaded sufficiently to
resist the pressure of steam in the cylinder at the middle of the stroke, but capable
of yielding to the pressure inside the hollow piston.
Theese arrangements or any of them may also be applied in conjunction with
an external jacket if required.
The second part of our Invention is accomplished as follows:-
As there is always an even pressure of steam-throughout the stroke in the space
between the double piston or hollow piston above described, we avail ourselves of
this result to relieve the weight pressing downwards, by forming the upper portion
of the periphery of the pistons exposed to the internal pressure a little larger in
area than the lower portion, so that the steam may press the piston upwards with
a force equivalent to that given by its dead weight downwards.
This mode of balancing the weight of the piston may be applied to any ordinary
piston by constructing same with a hollow steam space, into which steam may be
admitted through valvez, telescope tubes, or other suitable contrivance, as above
described, and providing an opening or openings at the bottom so as to cause the
steam to press upon a larger area at the top than at the bottom. This plan is also
applicable with compressed air or other fluid pressures.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Samuel Geoghegan and John Sturgeon in the Great Seal Patent
Office on the 25th April 1882.
SAMUEL GEOGHEGAN, of Saint James's Gate Brewery, Dublin, Ireland, and
JOHN STURGEON, of No. 3, Westminster Chambers, Victoria Street, London,
Civil and Mechanical Engineers.
"IMPROVEMENTS IN STEAM ENGINES."
Our Invention has for its object improvements in steam engines, and relates
firstly, to an improved method of beating the steam cylinder by live steam applied
internally instead of in an external jacket in the manner hitherto usually
employed; and secondly, to an improved mode of balancing the weight of bori-
zontal or inclined cylinder pistons, and also to the improvements made feasible
by the constant pressure inside the piston or between pistons, for the purpose of
keeping the packing tight. To carry out the first part of our Invention according
to one modification, we construct the steam cylinder about double the length
required for the stroke, and apply two steam pistons placed about the length of
the stroke apart on the piston rod, so as to leave space between the pistons into which
steam direct from the boiler is admitted, and thereby brought into direct contact
with the inner surface of the cylinder instead of outside, as heretofore. Thus as the
double piston travels forward it carries with it a body of boiler pressure steam
heating the cylinder in advance of the incoming or expanding steam, while the
portion of the cylinder from which the steam is exhausting, and does not require
heating (except in compound engines) is not heated unnecessarily as in the case of
an externally jacketed cylinder. Live steam from the boiler may be admitted to
the space between the two pistons through a passage formed in the centre of the
cylinder, and any condensed water may be drained off through an aperture or
passage suitably arranged for the purpose. According to another modification of
our Invention, instead of placing the two pistons the full stroke apart we arrange
them only a short distance from each other, and admit the steam to the space
between through a hollow tail rod, piston rod, or telescope tube passing through
the cylinder cover, or by means of any other suitable contrivance. Instead of the
double piston, as described in the above named modifications, a single piston may
be employed recessed in the middle, so as to form an annular steain space in the
piston, the periphery of which between the piston rings is left open or perforated,
thus bringing the steam into contact with the inner surface of the cylinder; and
in this case steam may be admitted to the interior of the piston through a valve
or valves opening inwards, or by means of a telescopic tube or other suitable
contrivance, admitting the steam either direct from the cylinder itself during
compression, or cushion, or from a pipe leading from the boiler. In applying a
piston thus arranged to a horizontal engine, we drain off the condensed water
through an opening formed about the centre of the cylinder and at the bottom
thereof, which opening is closed by a valve loaded sufficiently to resist the
pressure of steam in the cylinder at the middle of the stroke, but capable of
yielding to the increased pressure inside the hollow piston. These arrangements
or any of them may also be applied in conjunction with an external jacket if
required. This plan gives also over and above the ordinary benefits of an external
jacket, an increased facility for more perfect lubrication of pistons, and allows of
the use of superheated steam. The second part of our Invention is accomplished
as follows:-As there is always an even pressure of steam throughout the stroke
in the space between the double pistons or hollow piston above described, we avail
ourselves of this result to relieve the weight pressing downwards, by forming the

page_text: upper portion of the periphery of the pistons exposed to the internal pressure a
little larger in area than the lower portion, so that the steam may press the piston
upwards with a force equivalent to that given by its dead weight downwards.
This mode of balancing the weight of the piston may be applied to any ordinary
horizontal or inclined piston, by constructing same with a hollow steam space into
which the steam may be admitted through valves, telescope or sliding tubes, or
other suitable contrivance, as above described, and providing nu opening or
openings at the bottom so as to cause the steam to press upon a larger area at the
top than at the bottom. This arrangement of balancing the piston dispenses with
the necessity of a tail rod, stuffing box, etc., and prevents the cylinder and glands
wearing oval. This plan is also applicable with compressed air or other fluid
pressures.
The same letters refer to like parts to each figure.
Figure 1 shows a section of our long cylinder system
where the double 1
pistons A, A, are placed about the length of the stroke apart. Steam is admitted
at each end of the cylinder at B, B, and exhausted in the ordinary way.
The space C between the piston is always filled with live steam which enters
-at-d; an outlet e is provided with a cock to regulate the escape of any condensed
water.
Figure 2 shews a section of a vertical or inclined cylinder with hollow double
piston A, A. Steam is admitted into the space C in the piston through the
sliding tube d, which is attached to the piston and slides through a stuffing box f
in the cover, and enters another stuffing box g in the supply pipe h. A second
similar sliding tube may be provided for relieving the piston of any condensed 2
water that may accumulate.
Figure 3 shews a section ; and
Figure 4, an end view of a horizontal cylinder with a hollow double piston A, A.
Live steam is admitted at i through a sliding tube d into the hollow space C in the
piston. An outlet sliding tube e has an elbow f to carry off any condensed water
formed. The tubes d and c are attached to the piston and slide through stuffing
boxes into the socket pieces g and h. The outlet g is regulated by a cock j.
Figure 5 shews a section; and
Figure 6, an end view of a horizontal cylinder with hollow piston A, A, and one
sliding tube d for the admission of steam, and similar to those previously described
E is an outlet for condensed water with a grating and valve f with a spring or
weighted lever, so regulated as to open only in the middle of the stroke. The
pressure of steam inside the piston being greater than that in the cylinder at half
stroke, the valve opens and closes again as soon as the piston has passed. A waste
pipe may have a cock which is kept slightly open. By this arrangement the
ordinary condensed water cocks are not required, the well e in the centre being
sufficient to keep the cylinder dry.
Figure 7 shews another modification of double piston A, A, with two or more
spring valves d, d, opening inwards. An extra amount of cushion steam is
allowed, so as to fill the passages and hollow space C in the piston at the ends of
the stroke. The valves d, d, are set to open only during the compression or extra
pressure at each end of the stroke. Outlet valves e, e, arranged so as to carry off
the condensed water, and may be actuated automatically either by springs, weighted
levers or as shewn. Steam from the boiler is admitted at k, k, which acting on a
thin elastic metal disc to which the valve is fixed, keeps the valve closed until the
extra pressure, due to compression at the ends of the stroke, opens it and allows
the water to escape through f.
Figure 8 shews a vertical section of one of our balanced pistons; A, A, is the
body keyed on the rod so as to ensure the widest part being at the top; b, b, are
the covers; c, c, the ordinary parallel rings; D, D, are the taper rings proportioned

page_text: to the pressure of steam and weight. Steam is supplied inside the piston and is
maintained at an uniform pressure. The difference of acting area between the top
half m and the bottoin half n due to the taper form gives an upward pressure
equal to the weight of the piston and rod, etc.; l, l, are pins to prevent the rings
from turning.
Figure 9 shews the form of the taper rings D, D.
Figure 10 shews a vertical section of one half of another form of our balanced
piston; A, A, is the body with an uniform steam pressure inside the piston, and by
means of one or more openings d, d, the pressure is exerted on one side of the disc;
D, D, is a taper ring wider at the top than at the bottom, as in Fig. 8, but in the
form of an elastic curved disc, so that the steam pressure inside the piston keeps
the ring tight. A small hole is drilled through the piston rod and communicates
with the back of each ring at p and the atmosphere, so as to relieve the back from
pressure.
Figure 11 shews a similar arrangement to Fig. 10, but more suitable for large
cylinders. The disc rings D, D, are reduced to annular rings. The steam enters
at C through a sliding tube, and passes through openings d, d, pressing out the
rings D, D. The pressure is relieved from the back of the rings by openings p, p,
to the centre of the rod, and open to the atmosphere.
In witness whereof, I, the said John Sturgeon, for and on behalf of myself and
the said Samuel Geoghegan have hereunto set my hand and seal, this
Twentyfourth day of April, in the year of our Lord one thousand eight
hundred and eighty two.
Signed, sealed, and delivered by
the within named John Sturgeon
in presence of
W. HUDSON,
Engineer & Patent Agent,
Brixton,
London.
JOHN STURGEON. (L.S.)