Improvements in Steam Engines.
Year: 1895

page_text: Date of Application, 24th July, 1895
Complete Specification Left, 24th Apr., 1896-Accepted, 6th June, 1895
I, JAMES COURTHOPE PEACHE of No. 87 East Hill, Colchester, in the County
of Essex, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention consists, first, in the adaptation of single acting compound engines
such as described in my Patent 14,526, Aug. 27th 1891, to form a tri-compound
engine suitable for working with a vacuum.
For this purpose,
use three sets of double cylinders such as shown in
Figures 4, 5, 6, or 7, in the above Patent; all working on to a three throw crank
shaft. 1 arrange the connections for the steam supply in such a way that
H.P. steam is admitted to one only of the smaller cylinders of the three sets.
The exhaust from that cylinder is led to the two other small cylinders of the two
These three
other sets of cylinders, and also to the large cylinder of the first set.
cylinders, viz., two small and one large one, form the second stage. The exhaust
from these three cylinders is led to the remaining two large cylinders. This forms
the third stage in the tri-compound engine. Finally, the exhaust from these last
two large cylinders, is led to the condenser.
The details of the valves, pistons, and cylinders, are precisely the same as in a
three crank engine constructed from either Figures 4, 5, 6 or 7 of my Patent
above-mentioned, but instead of the connections to the steam chests and receivers
being made so as to make each small cylinder a H.P. cylinder and each large
cylinder a L.P. cylinder, the connections are made as described in the previous
paragraph.
This invention is applicable to any tandem compound single acting engine.
Improvements in Steam Engines.
I, JAMES COURTHOPE PEACHE, of No. 87 East Hill, Colchester, in the County
of Essex, 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 in steam engines, and consists in the
adaptation of single acting compound engines, such as for example, described in the
Specification of Letters Patent No. 14526, dated August 27th 1891, to form a
triple expansion engine suitable for working with a vacuum.
For this purpose I use three sets of tandem compound cylinders all acting on a
three-throw crank shaft. I arrange the connections of these cylinders in such a
manner that steam is first admitted to only one of the small cylinders of the three
sets, which thus serves for the first stage of expansion of the steam.
The exhaust.
from this cylinder is led to the small cylinders of the two other sets, and also to

page_text: we large cynner of the nrst set, these three cylinders serving for the second
stage of expansion. Then the exhaust from the aforesaid three cylinders is
conducted to the remaining two large cylinders of the second and third sets, which
are designed for the third stage of expansion in this engine. Finally, the exhaust
from the last two large cylinders passes to the condenser.
Instead of these three sets of tandem compound cylinders I may also employ two
sets in conjunction with a single cylinder, one part of which acts as the first stage
of expansion, and its other part together with the small cylinders of the two
sets as the second stage, whilst the large cylinders of these two sets serve for the
third stage of expansion.
Referring to the accompanying drawings which are to be taken as part of this
Specification and read therewith:-
Figure 1 represents a vertical transverse section of a single acting tandem
compound engine constructed in accordance with my above mentioned Patent
No. 14526 of 1891.
Figure is a rear elevation of an engine having three sets of similar tandem
compound cylinders arranged and connected in conformity with my said invention.
Figure 3 is a diagram showing a modified arrangement of the engine cylinders.
I will first briefly describe the action of the single acting tandem compound
engine shown in Figure 1, and then proceed to explain, with reference to
Figures 2 and 3, my improved mode of connecting either three sets of tandem
compound cylinders, or two such sets together with a single cylinder, to form a
triple expansion engine.
As above stated, the engine shown in Figure 1 is constructed in accordance
with my Patent No. 14526 of 1891, the cylinders, pistons, valves and valve-
controlling cylinder being arranged as set forth in the Specification of my said
Patent.
The steam entering the valve chest at A is admitted through the valve 7 and
port p to the upper side of the piston p in the small cylinder and through the
port also to the space 2 and the upper side of the piston r in the large
cylinder. Shortly after the commencement of the down-stroke the piston p passes
over the end of the port 3, thus cutting off the supply of steam above the piston r.
This steam expands for the remainder of the stroke, and is compressed again on
the return stroke. During this return stroke the steam above the piston p in the
small cylinder exhausts through the port p², and passes through openings ginto
the interior of the hollow piston valve g, and thence over the valve 9 and
through the port 8 into the large cylinder 6. The exhaust from this cylinder on
the down-stroke takes place through the port past the end of the valve g₁ to the
exhaust C.
With a view to obtaining a triple expansion engine, such as illustrated in
Figure 2, I connect three sets of similar tandem compound cylinders arranged to
act on a three-throw crank shaft, the cranks of which may be set at angles of 120°
relatively to each other or at any other angles that may be found desirable.
The branches 1, 4, 7 on the first set of cylinders, and 2, 5, 8 on the second set,
and 3, 6, 9 on the third set correspond to the branches A, B, C in Figure 1.
Steam is admitted at S to the branch 1 and acts above the piston in the upper
or small cylinder of the first set of cylinders, which thus serves for the first stage
of expansion. It is then exbausted into the receiver with which the branches 4, 2, 3
communicate for conducting the same to the second and third sets of cylinders
in order to act above their upper pistons, and at the same time to the under side
of the lower piston in the first set of cylinders, so that in lower or large cylinders
of the first set and the upper or small cylinders of the second and third sets
constitute the second stage of expansion of the steam. Next the exhaust from the
lower or large cylinder of the first set passes through the branch 7 to the
branches 5 and 6 on the receivers of, the second and third sets of cylinders, and
joins the exhaust from the upper or small cylinders of the second and third sets,
whereupon this exhaust steam is conveyel to the underside of the pistons in the

page_text: large cylinders of the second and third sets, this forming the third stage of
expansion. Through the branches 8 and 9 the steam is then conducted to the
condenser or final exhaust. The branch T supplies steam to the controlling
cylinders of the valves.
Although the engine represented in Figure 2 comprises three similar sets of
cylinders, it is evident that they may be made different without departing from the
scope of my invention. For instance, the ratio of the sizes of the upper and lower
cylinders constituting the first set may be smaller than is the case with those of the
second and third sets. Moreover, I place the sets of cylinders in any desired
sequence. Thus the set to which steam is first admitted may be arranged in the
middle instead of at one end as shown.
In a modification illustrated in Figure 3, I substitute for the set of tandem
cylinders to which steam is first admitted a cylinder p¹ p² of uniform size
throughout, dispensing with the controlling cylinder and providing for the holding
down power requisite to maintain the constant downward pressure by the difference
between the pressures of the steam on the two sides of the piston in this engine
cylinder. Under these conditions, the upper part p₁ of the said cylinder serves
for the first stage of the expansion of the steam, the lower part p² in conjunction
with the small cylinders p³ and p¹ of the two sets of tandem cylinders being used
for the second stage of expansion, whilst the third stage is constituted by the large
cylinders p and of the aforesaid sets of cylinders.
It will of course be understood that this improved mode of connecting three
sets of single acting compound cylinders to form a three-crank triple expansion
engine is applicable to any tandem compound single acting engine.
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. In single acting triple expansion engines, the combination of three sets of
tandem compound cylinders arranged to act on a three-throw crank shaft, and so
connected together that the small cylinder of the first set serves for the first stage
of expansion, the large cylinder of the first set and the small cylinders of the other
two sets for the second stage of expansion, and the large cylinders of these two
sets for the third stage of expansion, substantially as set forth.
2. In single acting triple expansion engines the combination of the two sets of
the tandem compound cylinders with a single cylinder, all arranged to act on a
three-throw crank shaft and so connected together that one part of the single
cylinder serves for the first stage of expansion, the other part of that cylinder and
the small cylinders of the two sets for the second stage of expansion, and the two-
large cylinders of these sets for the third stage of expansion, substantially as set.
forth.
D
CA
:11004
PHILLIPS & LEIGH,
No. 22 Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.