An Improved Compound Expansion Cylinder for Steam Engines, Pumps and the like.
Year: 1897

page_text: Date of Application, 27th May, 1897-Accepted, 28th Aug., 1897
COMPLETE SPECIFICATION.
An Improved Compound Expansion Cylinder for Steam Engines,
Pumps and the like.
I CONRAD SONDERMANN of 6, Landhausstrasse, Stuttgart in the Empire of Germany,
Civil 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:-
This invention has for its object a working cylinder forming a simplification of the
double expansion steam engine. It is suitable not only for ordinary engines but also
for marine engines, the engines of mining and smelting works, pumps with and
without flywheels, compressors, traction engines and locomotives. The cylinder may
also serve itself as a pump and compressor for gases. Finally, the cylinder may also
be employed as a water pump with a water motor in the same cylinder.
This improved cylinder is shown in longitudinal section in the accompanying
drawing, in combination with a piston distributing gear.
The essence of the invention consists in a steam cylinder a of approximately double
the usual length being reduced in section at its centre by a ring b. Two pistons c
and d in the wider parts of the cylinder are connected by a rod or tube e against
which the ring b fits tightly by means of rings pressing inwards. The cylinder is
thus divided into four chambers, the two inner ones ƒ and g forming the high
pressure cylinders, the two outer ones h and i forming the low pressure ones. Piston
valves are assumed to be employed in the present case for the steam distribution as
already stated, but the cylinder may of course be provided with any other suitable
arrangement of slide valves. It causes no difficulty if instead of piston slides, almost
unloaded flat slides be employed both for common as well as separate distribution of
the high- and low-pressure cylinders. Oscillating slide valves, may also be employed,
of similar construction to those employed in the present steam engines with deep
set valve slides. By the use of flat or oscillating valves the waste space in this
system of machines is very small.
Instead of piston flat or oscillating slides, valve and Corliss distributing gear may
also be employed. The machine may also be constructed as a vacuum-pump and
compressor with a cooling casing with only a flat slide for the distributing gear, such
as pumps with ordinary equalization of pressure are provided with.
For pumps which work with their own pressure water, the latter in the piston
movement shown, acts both in the solid cylinder h and also in the ring cylinder g,
whilst the water flows from the full cylinder i and is forced from the ring cylinder f
to the conveying pipe. On the return of the piston the pressure water flows into the
chambers i and f and from the cylinder h to the exit and from the ring cylinder g to
the conveying pipe. The slide distribution is then also so arranged that the passages
or ports of the solid cylinder are alternately placed in communication with the
pressure water and the exit, whilst the passages or ports of the ring cylinder are
connected simultaneously and also alternately with the pressure water and the
conveying pipe.
are
The principal advantages of this cylinder more particularly for steam engines

page_text: 1. Greater simplicity of construction and easy therefore cheap manufacture.
2. Considerably reduced constructive length as against the present arrangement
with separate high & low pressure cylinders lying one behind the other.
3. The use of only two cylinder covers and a single stuffing box, thereby requiring
less attention and yielding greater security of working as against the Woolf engine
with four cylinder covers, a connecting piece between the cylinders and three stuffing
boxes.
4. In many cases only one slide with one distribution for high and low pressure
cylinders, and always however one slide box, a separate receiver between the high
and low pressure cylinders being dispensed with.
5. Less waste space owing to very short passages more particularly where flat or
oscillating slides are employed and therefore a shorter duration of the compression,
that is to say a greater completeness of the diagram and a very reduced consumption
of steam.
6. An equal delivery of work during the outward and return stroke of the piston,
because the always greater charge in the high pressure cylinder on the outward
stroke, in this case also exerts a greater effect on the return stroke in the low pressure
cylinder. A similar equalization takes place in the always smaller charges of the
rear high and low pressure side and therefore
7. A very even travel even in machines with a low number of revolutions.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is.
A compound expansion cylinder for steam engines, pumps and the like,
characterised by a projecting ring (b) being arranged in the middle of the
cylinder (a), which ring tightly encloses a rod or tube (e) which connects with one
another two pistons (d) and (c) which are movable in the cylinder chambers thus
formed, in such a way that there are formed in the same cylinder-body two annular
chambers (f and g) serving as high pressure cylinder chambers and two cylinder
chambers (h and i) serving as low pressure cylinder chambers, which alternately
communicate with one another and with the steam supply and discharge by
means of any suitable distributing arrangement substantially as hereinbefore
described.
Dated this 25th day of May 1907
WM. P. THOMPSON & Co.,
Of 6 Lord Street, Liverpool, Agents for the Applicant.