Improvements in Steam Engines.
Year: 1894

page_text: Date of Application, 9th Nov., 1894
Complete Specification Left, 8th Aug., 1895-Accepted, 14th Sept., 1895.
Improvements in Steam Engines.
I, HENRY CAMBRIDGE of No. 12 Mountstuart Square, Cardiff, in the County of
Glamorgan, Consulting Engineer, do hereby declare the nature of this invention to
be as follows:-
My invention relates to improvements in compound steam engines. In carrying
it into effect, I make the L.P. piston and cylinder annular to the H.P. cylinder,
packing both sides of the L.P. piston. An annular space may separate the two
cylinders. The piston rods are led through the end cover or covers in any suitable
positions. The valve cylinder is parallel with the working cylinders and is fitted
with piston valves. The H.P. valves are fixed upon the ends of the valve rod and
the L.P. valves on the same rod and between them. The rod itself is tubular, there
being one tube inside the other.
Steam from the boiler enters the H.P. cylinder through the top part of the piston
valve and passes through circular ports in the usual way, the escaping exhaust steam
passing through the underside of the H.P. valve and down through apertures in the
piston valve tube and emerging through other apertures and into the underside of
the L.P. piston valve, the exhaust being carried away to the exhaust side of the
L.P. valve and away to the condenser as usual, the steam. acting on both sides of.
the piston in the same way.
The valves and pistons are worked in the usual way.
I may replace the L.P. piston valves with an ordinary slide valve, the steam chest
for this purpose occupying the central part between the two H.P. piston valves.
The L.P. slide valve may be worked from the H.P. piston valve or may have a
separate spindle of its own and be worked from a crosshead outside of both steam
chests, so that separate adjustment may be made when required.
Dated this 9th day of November 1894
PHILLIPS & LEIGH,
Agents for the Applicant.
Improvements in Steam Engines.
1, HENRY CAMBRIDGE, of No. 12 Mount Stuart Square, Cardiff, in the County
of Glamorgan, Consulting Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates to improvements is compound steam engines.
In order that it and the best means of carrying it into practical effect, may be
thoroughly understood, I will now describe it and them in detail, referring in so
doing to the accompanying drawings which are to be taken as part of this
Specification and read therewith.
Figure 1 is a longitudinal section through the cylinders of a compound horizontal
engine made according to the present invention.
Figure 2 is a longitudinal section illustrating a modification of the invention in
respect of the low pressure valve mechanism.

page_text: Figure 3 is a front elevation, partly in section, corresponding with Figure 2.
Figure 4 is a section on the line 4-4 of Figures 2 and 3.
The invention will be best understood by tracing the course of the steam.
A is the flange of the steam supply B to both ends of the steam chest C.
D, D are a pair of piston valves working within suitable valve cylinders E, E.
The latter have the necessary ports formed in their sides.
When the H.P. valves D are moved in the usual manner, the steam enters the
ports Fand G alternately. It is conveyed along a detachable steam pipe H, to
the ends of the H.P. cylinder 1, alternately. This cylinder is in the centre of the
cylinder arrangement, it being surrounded by the L.P. cylinder P and an
intermediate jacket c. J is the H.P. piston and K, the H.P. piston rod with the
necessary stuffing box in the cylinder cover L.
When the steam has finished its work in the H.P. cylinder, it escapes through
the steam ports M, M, alternately, into the L.P. steam chest N and passes from
there through the ports O, O, alternately, into the L.P. cylinder P.
Q, Qare the L.P. piston valves, with rings or their equivalent, fitted at
either end, the valve having a passage right through for its entire length to give
through communication for the steam. The cylinder P is made annular with
external walls R, R, and internal walls S, S. The piston T is also anuular and is
fitted with external packing rings U, and internal packing rings V. The packing
rings U work against the cylinder walls R, and the packing rings V, against the
inside walls S.
W, W are piston rods attached to the L.P. piston, the cylinder cover being fitted
with stuffing boxes X, X, of any convenient type.
After the steam has done its work in the L.P. cylinder, it escapes to the
condenser through the ports O, O, alternately, the annular space Y around the
L.P. vaive and the pipe Z.
The valve spindle a is made tubular for a certain portion of its length and
the H.P. steam passes down through the bore of it and a port b at its lower end, the
effect of this through communication being to keep the valve spindle hot and to
assist the superheating of the exhaust steam between the cylinders.
c is an annular space or steam jacket surrounding the walls of the H.P. cylinder.
In the modification illustrated in Figure 2, an ordinary D valve takes the place
of the L.P. piston valves illustrated in Figure 1. But this D valve is specially
adapted to be worked in connection with a pair of H.P. valves, applied to the same
system.
The central valve spindle upon the end of which the H.P. piston valves are
secured, is made hollow and of sufficient diameter to act as a continuation of the
steain pipe being thereby adapted to convey a portion of the steam from one chest
to the other.
A bridle arrangement or crosshead d communicates the motion from the eccentrics
to the valves.
e is a disc or junk ring placed upon the steam side of the piston valves, for the
purpose of providing the necessary lap, a thicker or thinner disc being employed
according to the lap required, or it may be chamferred at the outside as may be
required.
At the back of the large ☐ valve there is an annular recess in the steam chest
cover, within which fits a packing ring as commonly employed for this purpose.
The packing ring is split and provided with a tongue piece of suitable form, a
spiral spring being placed at the back of the ring for keeping the ring up to its
face on the back of the valve.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination of H.P. and L.P. cylinders of a steam engine
aa cat forth

page_text: 2. The combination of steam jacket, high pressure cylinder and low pressure
cylinder, as set forth.
3. The combination of valve spindle, axial bore therein and exhaust port, whereby
the temperature of the spindle is kept up, as and for the purpose set forth.
Dated this 8th day of August 1895.
PHILLIPS & LEIGH,
No. 22 Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.