HIGH SPEED STEAM ENGINES
Year: 1884

page_text: I AUGUSTUS BEVER of 20 Heaton Grove Bradford in the County of York,
engineer's draughtsman do hereby declare the nature of my invention for HIGH
SPEED STEAM ENGINES to be as follows:-
I place three single acting horizontal cylinders side by side on each side of a
three-throw crankshaft, all the cylinders being cast together and having formed on
the bottom a valve chest on which they stand, a bearing for the crankshaft being
also cast at each side. All the cylinders receive steam from a single slide valve..
The connecting rods from two opposite cylinders are coupled to the same crank and
hoops are passed around the two connecting rod ends to keep them in their places.
The two outside cranks are on the same centre and the centre crank forms an angle
of 180 degrees with them. The engine is to be worked compound and the diameters
of the cylinders must be so arranged as to make the pressure on two outside pistons
equal to the pressure on the centre one.
These pistons are of the form known as "trunks" and have pins for the small
ends of the connecting rods placed as far back as possible. The slide valve is so
arranged as to form a receiver for the steam coming from the high pressure
cylinders. For lubricating the crank pins a large oil cup is placed over them with
wicks hanging from oil syphons, the connecting rod ends being provided with horns
which lick a drop of oil off the wicks at each revolution. On one end of the crank-
shaft a governor is mounted, which works a throttle valve, thus regulating the
admission of steam and keeping the speed of the engine constant.
The valve gear
may also be so arranged as to be capable of varying the cut-off of stean in the
cylinders. The slide-valve is worked by an eccentric on the crankshaft, and if the
cut-off is to remain constant, this eccentric is connected directly to a rocking shaft,
which works the slide-valve in a direction at right angles to the crankshaft; but if
a variable cut-off is to be employed, I make the eccentric with a slot in which a die
works, thus varying the stroke of the valve and in consequence the cut-off of steam,
while the lead remains constant.
The ports from all the cylinders are brought to one plane face, so that they can
all be worked by one slide valve, those coming from the cylinders on each side of
the crankshaft forming one group. The ports farthest from the crankshaft are
those from the outside cylinders, and between these and the ports from the centre
cylinders the exhaust ports are placed.
The valve is made hollow, and the high pressure cylinders exhaust into the valve,
the low pressure cylinders drawing their steam from the inside. To facilitate the
working of the slide valve, I prefer to relieve it of a portion of the steam pressure
on the back.

page_text: I, AUGUSTUS BEVER, of 20 Heaton Grove, Bradford, in the county of York,
Engineer's Draughtsman do hereby declare the nature of the said invention for
"HIGH SPEED STEAM ENGINES "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 improvements in that class of steam engines having
more than one cylinder on each side of the crankshaft and the invention consists in
arranging and proportioning the cylinders in such a manner as to balance the
pressures from the cylinders on one side of the crank-shaft by the pressures from the
cylinders on the other side thereof whereby pressure on the crank shaft bearings is
reduced to a minimum thus greatly reducing the wear and tear of such engines and
rendering the working of the engines more steady.
I will describe my invention as applied to an engine having three cylinders on
each side of the crank shaft as this is the arrangement I prefer.
For this purpose I place three single-acting horizontal cylinders side by side on
each side of a three throw crankshaft; all the cylinders may be cast together
and may have a valve chest which forms the bottom on which they stand, a bearing
for the crankshaft is cast or bolted on each side. All the cylinders receive steam
from a single slide valve constructed as hereinafter described. The connecting rods
of each two opposite cylinders are coupled to the same crank and hoops are passed
around the two connecting rod ends to keep them in their places. The two outside
cranks are on the same centre and the centre crank forms an angle of 180° with
them. The engine is arranged to work compound and to obtain the balancing of
pressures above named the diameters of the cylinders are so proportioned and the
cylinders so arranged as to make the sum of the pressures on the pistons of the low
pressure cylinders on one side equal to the pressure on the piston of the high
pressure cylinder on the other side. These pistons are of the form known as trunks
and have pins for the small ends of the connecting rods placed as far back as
possible. If the engine is to run at a moderately high speed I place a large oil cup
over the connecting rods with wicks hanging from oil syphons and provide the
connecting rod ends with horns which lick a drop of oil off the wicks at each
revolution, but if a very high speed is to be employed I prefer to fill the whole
bottom portion of the engine casing with oil and allow the connecting rod ends to
dip in at each revolution. On one end of the crankshaft a governor is mounted
working a throttle valve for regulating the admission of steam in the ordinary way
and thus keeping the speed of the engine constant. Or the engine may be also
regulated by varying the cut-off of steam in the cylinders, in which case the valve
gear is arranged for this purpose as hereinafter described. The slide valve is
worked by one or more eccentrics on the crankshaft and if the cut-off is to remain
constant the eccentrics are connected directly to a rocking shaft which works the
slide valve in a direction at right angles to the crankshaft; but if a variable cut-off
is to be employed I make the eccentric straps with radial slots in which dies work;
by varying the position of these dies the stroke of the valve is altered while the lead
remains constant and in consequence the cut-off of steam will be altered.
The ports from all the cylinders are brought to faces in the same plane so
that they can all be worked by one slide valve, those coming from the cylinders on
each side of the crankshaft forming one group. The ports farthest from the
crankshaft are those from the outside cylinders and between these and the ports
from the centre cylinders the exhaust ports are placed. The valve is made hollow

page_text: and the high pressure cylinders exhaust into the valve, the low pressure cylinders
drawing their steam from the inside. To relieve the valve of a portion of the steam
pressure on the back and thus to facilitate its working, I admit the steam through
a relief frame at the back of the valve and connect this frame with the main valve
casting in such a way as to give a constant elastic pressure of the valve on its face
and of the relief frame on the bottom face.
In order to enable my invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawings in which figure 1, is a
longitudinal section, figures 2, and 3, are cross sections and figure 4, is a plan partly
in section of a six cylinder engine constructed according to my invention. Figure 5,
is a longitudinal section shewing my improved variable cut-off gear. Similar
letters in all the figures represent similar parts.
A, A, are the high pressure cylinders; B, B, the low pressure cylinders. In the
drawings the high pressure cylinders are shewn in the centre and the low pressure
cylinders outside, but if more convenient I can reverse the order and put the low
pressure cylinders in the centre and the high pressure cylinders outside. In figure 1,
the section on the left hand side is through a low pressure cylinder and on the
right hand side through a high pressure cylinder; a, a, are the connecting rods
from the high pressure cylinders and b, b, two of those from the low pressure
cylinders. Around the large ends of the connecting rods, hoops k, are fastened to
keep the rods in their places.
D, is the crankshaft projecting at each side through bearings and stuffing boxes c, c;
d, is the crank for the two high pressure cylinders and e, e, the cranks for the low
pressure cylinders. The eccentric sheaves f, are turned solid out of the webs of the
shaft. The eccentric straps are connected to the rocking shaft F, which in its turn
works the valve spindle i.
Figure 5, shews the arrangement for varying the cut-off of steam in the cylinders;
the eccentric straps g, are held and guided on one side by the link and have on the
other side a radial slot h, in which a die m, works; the position of this die can be
altered by the link n, connected to the rocking shaft o, which can be set by a hand
lever or other arrangement. This valve gear is capable of working the engine in either
direction according to the position of the die in the slot on one side or the other of
the centre line.
The steam enters the throttle valve V, and passing through the passage C, follows
the direction of the arrow shown in figure 1, entering the slide valve through the
relief frame r, the valve ports p, opening in their turn to the high pressure cylinder
ports Q. After having done its work in the high pressure cylinders the steam is
exhausted through the valve ports s, and from there passes to the low pressure
cylinder ports t, afterwards being exhausted through the port u, and passing to the
exhaust nozzles w. The areas of the opening x, in the back of the valve and of the
relief frame r, are so proportioned as to leave a slight pressure on the valve and
relief frame to keep them up to their respective faces.
I have described my invention as applied to a six cylinder engine but it will be
obvious that the principle of balancing the pressures is equally applicable to engines
having other numbers of cylinders as will be understood without further
description.
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 :-
(1). In a compound steam engine having more than one cylinder on each side of
the crankshaft, balancing the pressures in the low pressure cylinder or cylinders on
one side of the crankshaft by the pressure in the high pressure cylinder or cylinders
on the opposite side of the crank shaft as hereinbefore described.
(2). The improved six cylinder compound engine constructed, arranged and
operating substantially as herein described and represented in the accompanying
drawing.

page_text: (3). A slide valve for working all the cylinders of a compound engine in which
the high pressure steam is admitted at the back of the valve and the low pres-
sure steam passes through the valve substantially as herein before described and
represented in figures 1, and 2, of the accompanying drawing.
(4). An arrangement of valve gear with an eccentric strap held and guided by a
link on one side and provided with a radial slot on the opposite side in which a die
can be adjusted to vary the cut-off of steam in the cylinders of a steam engine with
the engine going in either direction as herein before described and shewn in figure 5,
of the accompanying drawing.