Improvements in Multiple Expansion or Compound Engines.
Year: 1887

page_text: Date of Application, 15th Sept., 1887;
Specification Accepted, 18th Oct., 1887
COMPLETE SI MINICATION.
Improvements in Multiple Expansion or Compound Engines.
I WILLIAM ALLAN of Scotland House Sunderland in the county of Durham
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 relates to certain improvements in multiple expansion or compound
engines and has for its object the better arrangement of the parts of such engines so
that greater simplicity of construction combined with other important advantages
hereinafter set forth may be obtained whereby greater working efficiency results.
My improvements are chiefly but not exclusively applicable to inverted cylinder or
horizontal cylinder engines having two or more cylinders for the successive or
multiple expansion of steam. The invention consists essentially in arranging some or
all of the cylinders in pairs transversely or at right angles to the line of the crank
shaft, and connecting the piston rods of each such pair to one cross head and one
crank. Where an even number of cylinders is employed they may all be arranged in
transverse pairs, or certain of them in transverse pairs and certain of them lineable
with the crank shaft; and where an odd number is employed the odd one is placed in
the usual position relative to the crank shaft. By this arrangement in an ordinary
two cylinder compound engine one crank only is required. In a triple expansion
engine by arranging the first and second cylinders transversely and the third in the
usual manner a two crank engine results. For a two crank quadruple expansion
engine the first and second cylinders and the third and fourth cylinders may be
placed transversely or the same engine may be arranged for a three crank engine by
placing the first and second cylinders transversely and the third and fourth lineable
with the crank shaft. For a three crank quintuple expansion engine the first and
second and the third and fourth cylinders may be arranged transversely and the
fifth as usual, and for a three crank sextuple expansion engine all three pairs may be
arranged transversely or certain of them in the usual manner according to the
number of cranks required.
I will now more fully describe my improvements in reference to their application
to a quadruple expansion or four cylinder marine engine. I have illustrated such an
arrangement in the accompanying drawings in which figure 1 is a plan, and figure 2

page_text: a fore end elevation of the engine showing position of the first and second cylinders
in relation to the crank shaft, also the piston rods and connections; in this case the
cylinders are arranged so that a three throw crank shaft is employed. A¹ A² A³ A*
are the four cylinders. The high pressure or first expansion cylinder A¹ and the
second expansion cylinder A' are arranged transversely to or at right angles with the
line of the crank shaft S, both being jointed or cast together, the piston rods a¹ a³ of
the said cylinders A' A² being secured to the one cross head C to which the one
connecting rod R for the first or forward crank is attached. The third expansion
cylinder A and the fourth or low pressure cylinder A* in the design are placed in
line with the crank shaft S, their piston rods being attached to their respective con-
necting rods and cranks in the usual manner, but if it were desired to obtain a two
crank engine the third and fourth expansion cylinders may be arranged and
connected in a similar manner to that above described for the first and second
expansion cylinders.
In the figures I have illustrated the application of my ring slide valves and my
patent gear for working same, but it will be obvious that steam may be admitted to
and exhausted from cylinders arranged on the principle above specified by ports and
slide valves arranged and worked in the usual manner.
With the above described arrangement of multiple expansion engines the following
important advantages are secured.
1. The strains are better disposed than in the existing arrangements of quadruple
expansion two crank engine of tandem type.
2. The number of cranks may be reduced and with three or four cylinders a two
or three throw crank engine may be obtained as desired.
3. Economy of space, for example, no more room is required for a quadruple
expansion engine than for a tandem or triple expansion engine constructed on usual
principles.
4. Facility for overhauling and examination.
5. Less material and consequent reduced cost of manufacture.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is :-
1. The improvement in multiple expansion engines consisting of arranging
cylinders in pairs transversely to or at right angles to the line of the crank shaft in
the manner and for the purposes hereinbefore set forth.
2. The hereinbefore described arrangement of cylinders for dual, triple, quadruple,
quintuple, or sextuple expansion engines whereby single double or triple crank
engines may be obtained.
Dated this Fourteenth day of September 1887.