Year: 1888

page_text: Date of Application, 19th Jan., 1888
Complete Specification Left, 18th Oct., 1888
Complete Specification Accepted, 23rd Nov., 1888
I, HERBERT LINDLEY, of Sandon Works, St. Simon Street, Salford, in the County
of Lancaster, a member of the firm of Browett Lindley & Co., Engineers, do hereby
declare the nature of this invention to be as follows:-
My invention relates to what are known as compound tandem engines and has for
object to so arrange the ports valves and other parts as to produce engines more
simple and efficient in construction and operation than engines of the class referred
to as heretofore usually made. In an engine according to my invention there is but
one valve chest wherein are both the valves for high and low pressure cylinders and
the ports to the high pressure cylinder are crossed or reversed as hereinafter described
for the purpose mentioned.
An arrangement of such an engine is as follows:-
The larger or low pressure cylinder is placed the further away from the crank in
order that the pistons may conveniently be removed by breaking the joint of the low
pressure cylinder cover: the two cylinders are formed in one casting and there is as
already stated but one valve chest to the two cylinders wherein are both the valves
for high and low pressure cylinders. Between the high and low pressure cylinders
is placed a mid-plate or diaphragm containing a self adjusting metallic packing
around the common piston rod and which serves to separate the two cylinders and
prevent steam passing from one to the other otherwise than by the proper ports
provided for this purpose.
A piston valve is employed to distribute steam to the high pressure cylinder and a
slide valve for the low pressure. Steam is admitted to the centre of the piston valve
and exhausts directly from the high pressure cylinder into the valve chest, whence it is
admitted by the slide valve into the low pressure cylinder. It is to be noted that
supposing both pistons are at the end of their stroke say away from the crank, steam
will require to be admitted to the same side of each piston viz. high pressure steam to
the H.P. piston and low pressure steam from the valve chest to the L.P. piston. In
order to obtain this distribution with the valves mentioned I make the ports to the

page_text: H.P. cylinder crossed or reversed so that the motion of the slide valve in the requisite
direction for admitting steam to the low pressure cylinder is in the same direction as
that required by the piston valve for the H.P. cylinder which, as steam is in the
centre is an exhaust stroke as regards its corresponding edge and if the ports were not
crossed would be in the wrong direction. I am therefore enabled to work both valves
off the same spindle and only one eccentric is required to actuate them. In order to
save room the two pistons are secured on to the rod with a single nut at the end of
the rod, a tubular distance piece serving to keep the pistons at their correct distance
apart. The self adjusting metallic packing between the two cylinders may be of any
suitable construction but should be contained in a loose plate or diaphragm secured in
such a way as to be removable so that the high pressure piston can be removed
without difficulty.
>
By this construction compactness and simplicity are obtained by doing away with
covers and joints between the cylinders and by having only one eccentric for both
valves and also by having only one valve chest and by the absence of connecting pipes
between the cylinders. Also the highly heated high pressure piston valve casing
being located in the valve chest in the midst of the steam for the low pressure cylinder
acts as a superheater and to a certain extent performs the office of a steam jacket to
the low pressure cylinder. The steam moreover passes from one cylinder to the other
with a minimum of friction and loss by radiation.
Dated this 19th day of January 1888
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W C.,
Agent for the Applicant.

page_text: Compo
I, HERBERT LINDLEY, of Sandown Works, St. Simon Street, Salford, in the
County of Lancaster, a member of the firm of Browett Lindley & Co. Engineers 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 what are known as compound tandem engines, and has for
object to so arrange the ports, valves, and other parts, as to produce engines more
simple and efficient in construction and operation than engines of the class referred
to, as heretofore usually made. In an engine according to my invention there is but
one valve chest wherein are both the valves for high and low pressure cylinders, and
the port passages to the high pressure cylinder are crossed or reversed as hereinafter
described for the purpose mentioned.
An arrangement of such an engine is as follows:-
The larger or low pressure cylinder is placed the further away from the crank in
order that the pistons may conveniently be removed by breaking the joint of the low
pressure cylinder cover: the two cylinders are formed in one casting, and there is,
as already stated, but one valve chest to the two cylinders, wherein are both the valves
for high and low pressure cylinders. Between the high and low pressure cylinders
is placed a mid plate or diaphragm containing a self-adjusting metallic packing
around the common piston rod, and which serves to separate the two cylinders and
prevent steam passing from one to the other, otherwise than by the proper ports
provided for this purpose. A piston valve is employed to distribute steam to the high
pressure cylinder, and a slide valve for the low pressure. Steam is admitted to the
centre of the piston valve, and exhaust directly from the high pressure cylinder into
the valve chest, whence it is admitted by the slide valve into the low pressure
cylinder. It is to be noted that supposing both pistons are at the end of their stroke,
say away from the crank, steam will require to be admitted to the same side of each
piston, viz. high pressure steam to the H.P. piston, and low pressure steam from the
valve chest to the L.P. piston. In order to obtain this distribution with the valves
mentioned I make the port passages to the H.P. cylinder crossed or reversed, so that
the motion of the slide valve in the requisite direction for admitting steam to the low
pressure cylinder is in the same direction as that required by the piston valve for
the H.P. cylinder.
I am therefore enabled to work both valves off the same spindle, and only one
eccentric is required to actuate them.
In order to save room, the two pistons are secured on to the rod with a single
nut at the end of the rod, a tubular distance piece serving to keep the pistons at
their correct distance apart. The self adjusting metallic packing between the two
cylinders may be of any suitable construction but should be contained in a plate
or diaphragm secured in such a way as to be removable, so that the high pressure
piston can be removed without difficulty.

page_text: By this construction compactness and simplicity are obtained by doing away with
covers and joints between the cylinders, and by having only one eccentric for both
valves, and also by having only one valve chest and by the absence of connecting
pipes between the cylinders. Also the highly heated high pressure piston valve
casing being located in the valve chest in the midst of the steam for the low pressure
cylinder, acts as a super heater, and to a certain extent performs the office of a steam
jacket to the low pressure cylinder. The steam, moreover, passes from one cylinder
to the other with a minimum of friction and loss by radiation.
In the accompanying sheet of illustrative drawings:-
:-
Fig. 1 is an elevation of a vertical compound tandem engine constructed according
o my invention.
Figs. 2, 3 and 4 are respectively a vertical section, a side elevation and a sectional
plan shewing to a larger scale, my improved arrangement of cylinders, valves and
steam passages. The same letters of reference are used to indicate like parts in the
several views wherein they appear. In Fig. 1, A is a low pressure cylinder placed
above the high pressure cylinder B; the pistons of both are connected to the crank C
in the usual manner by means of a piston rod E and a connecting rod. F is the
eccentric for working the valves the construction and arrangement of which I will
now explain with particular reference to Figs. 2, 3 and 4. In these figs. the high and
low pressure pistons G and H are secured in any well known manner to the rod E
common to both, a tube E¹ serving as a distance piece between them and forming a
shoulder for the low pressure piston H. D is the valve chest common to both
cylinders, with which it may be cast in one piece as shewn. I is a port passage that
leads from a convenient face on the outside of the cylinder casting arranged for the
connection thereto of a governor or stop valve for controlling the entrance of steam
from a boiler. This passage leads to a planed face inside the steam chest, on to which
face the piston valve casing J is secured and is so arranged as to admit steam to the
annular recess or cavity surrounding the central portion of the piston valve K. The
steam port passages to the high pressure cylinder are shewn respectively at L and M;
they are in communication with ports formed in the before mentioned planed facing
in the valve chest to which the piston valve casing J is bolted. The upper port M²,
however, corresponding to the passage M communicates with the lower end of the
cylinder B and the lower port L corresponding to the passage L, communicates with
the upper end of the said cylinder the passages L M being crossed for that purpose
and conveniently arranged the one beside the other as shewn in fig. 2.
The piston valve K is actuated by its rod N which in turn receives motion from the
eccentric F on the crank shaft. This rod N is prolonged and to it is attached the
ordinary slide valve O which distributes steam in the usual manner to the low pressure
cylinder A through the port passages P P¹ which are not crossed. On referring to
fig. 2, it will be readily seen that a downward movement of the valve spindle N will
cause the valve K to admit steam through the lower port L' and passage L to the
upper side of the high pressure piston G, and the slide valve O will also admit steam
from the valve chest to the upper side of the low pressure piston H through the
passage P; thus both pistons will receive an impulse in the same direction. The
exhaust from the high pressure cylinder takes place in the ordinary way past the outer
edges of the piston valve K directly into the valve chest D from which the steam is
drawn for the low pressure cylinder. The exhaust from this cylinder takes place in
the ordinary way through the central cavity in the valve O and an exhaust port R
into the atmosphere or into a condenser or other desired place. The return strokes of
the pistons are made in an exactly similar manner, the course of the steam through
the various ports being reversed by the valves as is well understood. Qis a plate or
diaphragm interposed between the two cylinders and formed with a recess in which is
arranged suitable metallic packing Q' that is held in place by a cover Q2.
This packing is arranged to fit the piston rod E in such a manner as to prevent the
passage of steam from one cylinder to the other except by means of the ports and
passages provided for that purpose.

page_text: 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 a compound tandem engine, a high pressure cylinder constructed with crossed
passages for motive fluid, in combination with a piston valve for distributing steam to
the said cylinder and a slide valve for distributing steam to the low pressure cylinder
substantially in the manner and for the purposes described and set forth.
2. My improved compound tandem engine constructed, arranged and operating in
the manner hereinbefore described with reference to and illustrated in the drawings
annexed.