Year: 1887

page_text: Date of Application, 6th Apr.. 1887
Complete Left, 6th Jan., 1888
Complete Accepted, 2nd Mar., 1888
I ARTHUR GEORGE BROWN of 5 Osborne Villas, Cathcart, Scotland Engineer
do hereby declare the nature of this invention to be as follows:-
This invention relates to that class of motive power engines which have what are
known as high and low pressure cylinders, the pressure after being utilized in the
former passing to the latter through a suitable valve and being there allowed to further
expand before being exhausted to a condenser or to waste.
For convenience of illustration I will describe my invention when applied in what
is known as a triple expansion and also in a four cylinder engine. For such engines
I so arrange and combine the parts that the exhaust from the first high pressure
cylinder goes to the top of the second low pressure cylinder from whence it passes to
the bottom of the second low pressure cylinder and then finally exhausts to a condenser
or to waste.
The exhaust from the top of the second high pressure cylinder acts in the same way
upon the first low pressure, and thus I get a final exhaust pulling in the same direction
and at the same time as the piston moves in the high pressure cylinder. A convenient
construction of piston for a double expansion four cylinder engine is one formed of a
solid bar fitting the top or high pressure cylinder passing thence to and through the
low pressure cylinder and carrying a piston therein and finally being suitably con-
nected with the crank shaft. A similar construction is applicable for a triple expansion
engine except that to produce a difference of area between the top and bottom of the
low pressure piston the piston rod from the bottom is considerably reduced in area
and passes through a suitable stuffing box before being attached to the connecting rod.

page_text: I prefer to use in such engines, valves substantially of a maltese cross section,
working in cylindrical pressure chests and performing only a partial rotation, being
also provided with a groove or communicating port which momentarily opens com-
munication between the cylinders of the same class, such valves being more fully
described in an application for a patent filed by me and of even date herewith but I
do not confine myself to the use of such valves in the construction of engines herein-
before indicated.
1
ין
A
1 1007
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION,
Improvements in Compound or Expansion Engines.
I, ARTHUR GEORGE BROWN of 5 Osborne Villas, Cathcart, Scotland, Engineer do
hereby declare the nature of this invention and in what manner the same is to he
performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to that class of motive power engines which have what are
known as high and low pressure cylinders, the pressure after being utilized in the
former passing to the latter through a suitable valve and being there allowed to further
expand before being exhausted to a condenser or to waste.
For convenience of illustration I will describe my invention when applied in what
is known as a
triple expansion and also in a four cylinder engine. Such an engine
is illustrated in the accompanying drawings in which Figure 1 represents a sectional
elevation through the four cylinders and the valve and Figure 2 an elevation on
the line.
Valves substantially of a maltese cross section, working in cylindrical pressure
chests and performing only a partial rotation being also provided with a groove or
communicating port which momentarily opens communication between the cylinders
of the same class may be used with these engines, and such valves are fully described
in an application for a patent filed by me and of even date herewith but I do not
confine myself to the use of such valves in the construction of the engines and
therefore show a species of cylindrical slide valve as from my said specification of
even date the application of my improved valve will be clearly understood.
In the drawings A A¹ are the high pressure cylinders which carry pistons a a¹ while
the low pressure cylinders B B' carry pistons 6, 6, pistons ab being carried by one
piston rod, and pistons a¹ 61 by a second.
C is the steam inlet, D the exhaust and E the hollow valve.
When the parts are in the position shown, the steam entering by C passes around
the space or recess 1 in the valve and thence to top of piston a in cylinder A, the
valve at the same time is opening the exhaust from the top of piston a¹ from whence
the steam passes by recess 2 to the top of piston b, in cylinder B; and the exhaust
from beneath piston is opened to discharge D. As pistons ab travel down their
respective cylinders the valve cuts off steam from the top of piston a and opens the
exhaust from above said piston through the centre of the hollow valve E to the top of
piston 6, steam at the same time being admitted to the top of piston a¹ and the
exhaust opened to discharge from beneath piston b'. In the meantime the exhaust
from the top of piston has been opened to the bottom of said piston through recess 3
in the valve and if a condenser be employed I will thus secure a final exhaust pulling
in the same direction and at the same time as the high and low pressure pistons on
the same piston rod are moving.
It will be understood that the complete operation alternately takes place in
cylinders A, B, and A¹, B, and that the valve E is operated from the crank shaft in
the usual manner.

page_text: It will be noted on reference to the drawings that there is a considerable difference
between the top and bottom area of the low pressure piston, the effect of this con-
struction being that as communication is opened through recess 3, the pressure per
square inch is practically equalized on the top and bottom of said piston, and the
tendency is to raise said piston, and thus the wear on the crank and wrist pins, as also
on the bearings is minimized. On the down stroke of the piston the valve cuts off
the final exhaust before the piston reaches its lowest point thus entrapping a portion
of the steam which forms a cushion in the cylinder and relieves the pressure on the
bearings and pins.
I am aware that it is not new in single acting four cylinder engines to exhaust from
the top of the high pressure cylinder on one side to the top of the low pressure cylinder
upon the other but in this construction the final exhaust has always been taken from
the top of the low pressure piston and to this construction I lay no claim, but
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-
:-
)
In compound or expansion engines the arrangement and combination of parts in
such a manner that the exhaust from the high pressure cylinder passes to the
top of the piston in the low pressure cylinder and from thence to the bottom of said
piston before being finally exhausted, substantially as described and for the purposes
set forth,
Dated this 6th day of January 1888.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London,
Applicant's Agent.