Improvements in Steam, and other Engines.
Year: 1892

page_text: Date of Application, 20th Aug., 1892
Complete Specification Left, 20th June, 1893-Accepted, 22nd July, 1893
PROVISIONAL SPECIFICATION.
Improvements in Steam, and other Engines.
I, MARK HEATON ROBINSON, of Picton House, Thames Ditton, in the County
of Surrey, Engineer, do hereby declare the nature of this invention to be as
follows:
The object of these improvements is to simplify the construction of single acting
steam engines. The valve which admits and cuts off the steam to the cylinder is
moved directly by, and is rigidly attached to, the piston itself, and the steam is
exhausted from the cylinder by the uncovering of ports by the piston towards the
end of its effective stroke.
I form the steam cylinder with a smaller cylinder hereafter called the valve
cylinder immediately (in a vertical engine) above it and concentric with it. There
is no division between the cylinders, and they are preferably made in one casting.
The upper end of the upper cylinder forms the steam chest or is in communication
with it. In the upper cylinder a second and smaller piston (hereafter called the
valve piston) works, connected to the main piston by a suitable valve stem or
distance piece. Admission ports are formed in the circumference of the upper
cylinder in such position that after the valve piston has travelled through a
prearranged portion of its stroke, it covers the ports and prevents the further
admission of steam which then expands in the cylinder.
Towards the end of the working stroke the main piston uncovers exhaust ports
in the circumference of the steami cylinder, and the steam escapes either directly
into the atmosphere or condenser; or into a chamber from which it may be
subsequently passed into the atmosphere or condenser; or, in a compound engine,
into a chamber forming the steam-chest of a second or low-pressure cylinder, such
low-pressure cylinder being placed either immediately below the first cylinder, or
side by side with it. On the up or non-effective stroke after the exhaust ports are
closed by the main piston, the steam then contained in the cylinder is compressed
until the upward movement of the valve piston uncovers the steam ports. The
clearance space is so proportioned that a sufficient volume of steam is available for
expansion in the cylinder, notwithstanding that cut-off may take place at a very
early part of the stroke.
The valve-piston may be loose on its stem and so mounted as to have a small
travel endways. If so arranged, it will lag behind on the upstroke, and will not
commence to uncover the steam-ports until just before the end of the stroke. The
steam which then enters the cylinder will force the valve piston upwards against an
upper stop on the valve-stem, where it will be in proper position for cutting off at
the right time on the succeeding down stroke, the areas exposed to the steam
pressure on the upper and under sides of the valve piston being suitably
proportioned.
Instead of a valve piston working in a fixed cylinder, there may be a moveable
cylinder attached to the steam piston, passing through a gland in the cylinder cover
into the steam chest above, the steam ports being in such moveable cylinder, and
opened and closed to steam by the passage of the said cylinder through the gland,
or through a moveable gland the position of which is controlled by the governor or
otherwise, so as to give a variable cut-off.
In case the steam is not to be exhausted directly into the atmosphere or condenser,
but through an intermediate chamber (called the "transfer-chamber") the latter is
formed by a downward extension of the steam cylinder closed beneath, the exhaust
ports in the cylinder being so arranged that when the steam exhausts it merely
passes from the space above the piston to the transfer-chamber or space below it.

page_text: On the piston-rod is fixed, at a suitable distance below the steam piston, a second
valve piston, similar to that which admits steam to the engine. It works also in a
valve cylinder, the ports in the circumference of which communicate with the
transfer-chamber; the valve cylinder is formed in, or is attached to, the lower cover
of the transfer chamber, and forms, with the lower piston-valve, the gland by which
the piston-rod passes through such cover. The lower end of the lower valve-
cylinder is open to the exhaust or to the condenser, and the ports in its circumference
are of such depth that they are uncovered by the lower valve-piston during the
whole of that part of the stroke during which the steam is not exhausting from the
cylinder. The steam-cylinder is thus never in direct communication with
the atmosphere or condenser.
In a tandem compound engine the lower end of the lower valve-cylinder above
described opens into the low pressure cylinder, the lower valve piston forming the
steam admission and cut-off valve of such low-pressure cylinder. The exhaust
from the low pressure cylinder is arranged in one or other of the ways already
described. The depth of the steam admission ports is in this case such as to give
the desired cut-off in the low-pressure cylinder as in the steam cylinder first
described.
It is obvious that what is here described as to the admission and exhaust of steam
will also apply to that of compressed air, or any other elastic motive fluid; also that
the engine as described may be used as a pump for compressing elastic fluids. The
terms up and down, above and below, used in this description, require appropriate
modification to adapt it to the case of a horizontal engine.
In order to limit rotation to one direction I attach a
other rotary part so arranged as to engage with a fixed circular rack at starting and
pawl to the fly wheel or
stopping but lifting out of the rack by centrifugal force while the engine is
running fast.
Dated this 20th day of August 1892
MARK H. ROBINSON.
COMPLETE SPECIFICATION.
Improvements in Steam and other Engines.
I, MARK HEATON ROBINSON, of Picton House, Thames Ditton, in the County
of Surrey, 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 :-
The object of these improvements is to simplify the construction of single acting
steam engines. The valve which admits steam to, and cuts it off from, the cylinder
is moved directly by, and is rigidly attached to the piston itself, and the steam is
exhausted from the cylinder by the uncovering of ports by the piston towards the
end of its effective stroke.
I form the steam cylinder with a smaller cylinder, hereafter called the valve
cylinder immediately (in a vertical engine) above it. There is no division between
the cylinders, and they are preferably made in one casting. The upper end of the
valve cylinder forms the steam chest or is in communication with it. In the valve
cylinder a second and smaller piston, hereafter called the valve piston works
connected to the main piston by a suitable valve stem or distance piece. Admission
ports are formed in the circumference of the valve cylinder, in such position that
after the valve piston has travelled through a pre-arranged portion of its stroke, it
covers the ports and prevents any further admission of steam which then expands
in the cylinder.
The admission of steam may be controlled by a sleeve sliding on the outside of
the valve cylinder, and covering the ports in its circumference more or less com-
pletely according to its position. It may be moved up and down by any suitable
form of governor, or by hand gear.

page_text: Towards the end of the working stroke the main piston uncovers exhaust ports in
the circumference of the steam cylinder, and the steam escapes either directly into
the atmosphere or condenser, or into a chamber from which it may be subsequently
passed into the atmosphere or condenser; or in a compound engine into a chamber
forming the steam chest of a second or low pressure cylinder, such low pressure
cylinder being placed either immediately below the first cylinder, or side by side
with it. On the up or non-effective stroke after the exhaust ports are closed by the
main piston, the steam then contained in the cylinder is compressed until the upward
movement of the valve piston uncovers the steam ports. The clearance space is so
proportioned that a sufficient volume of steam is available for expansion in the
cylinder, notwithstanding that cut off may take place at a very early part of the
stroke.
Instead of a valve piston working in a fixed cylinder, there may be a moveable
cylinder attached to the steam piston, passing through a gland in the cylinder cover
into the steam chest above, the steam ports being in such moveable cylinder and
opened and closed to steam by the passage of the said cylinder through the gland,
or through a moveable gland, the position of which is controlled by the governor
or otherwise, so as to give a variable cut off.
In case the steam is not to be exhausted directly into the atmosphere or
condenser, but through an intermediate chamber called the transfer chamber, the
latter is formed by a downward extension of the steam cylinder, closed beneath, the
exhaust ports in the cylinder being so arranged that when the steam exhausts, it
merely passes from the space above the piston to the transfer chamber, or space
below it. On the piston rod is fixed, at a suitable distance below the steam piston,
a second valve piston similar to that which admits steam to the engine. It works
also in a valve chamber, the ports in the circumference of which communicate with
the transfer chamber; the valve cylinder is formed in or is attached to the lower
cover of the transfer chamber, and forms with the lower piston valve, the gland by
which the piston rod passes through such cover. The lower end of the lower valve
cylinder is open to the exhaust or to the condenser, and the ports in its circum-
ference are of such depth, that they are uncovered by the lower valve piston
during the whole of that part of the stroke during which the steam is not exhausting
from the cylinder. The steam cylinder is thus never in direct communication with
the atmosphere or condenser.
Instead of the valve piston, a moveable cylinder attached to the steam piston may
be employed, similar to that which admits steam in the second case mentioned
above working through a gland in the lower cover of the steam cylinder. The
lower end of this moveable cylinder is open and in communication with the atmo-
sphere or condenser. Near the upper end are ports in the circumference connecting
the space below the piston with the atmosphere or condenser, and they are so placed
that they enter the glaud and cut off this connection at the proper period of the
stroke viz.: during the period that the steam is being exhausted from the upper
side of the working piston.
In a tandem compound engine in which the admission and exhaust are controlled
as in the engine described above, the lower end of the lower valve cylinder opens
into the low pressure cylinder, the lower piston valve forming the steam admission
and cut off valve of such low pressure cylinder. The exhaust from the low pressure
cylinder is arranged in one or other of the ways already described. The depth of
the steam admission ports is in this case such as to give the desired cut off in the
low pressure cylinder, as in the cylinder first described.
It is obvious that what is here described as to the admission and exhaust of steam
will also apply to that of compressed air, or any other elastic motive fluid; also
that the engine as described may be used as a pump for compressing elastic fluids.
The terms up and down, above and below, used in this description, require
appropriate modification to adapt it to the case of a horizontal engine.
In order that my said invention inay be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.

page_text: Figure I is a vertical section of the engine as first described. A is the steam
cylinder and B the valve cylinder in which work the steam piston G and valve
piston C respectively. At the top of the stroke steam enters the steam cylinder
from the steam chest D by the ports E in the valve cylinder and forces the piston G
downwards and with it the valve piston C. At a certain point this piston covers
the ports E in the valve cylinder B and cuts off the steam which then expands in
the steam cylinder. At a point near the end of the stroke the steam piston G
uncovers the ports F in the steam cylinder, and during the passage of the piston to
the bottom of the stroke and back again to this point, steam exhausts either into
the atmosphere or the condenser. During the remainder of the upstroke, until the
ports E are again uncovered by the valve piston C the steam in the cylinder A
above the piston G is compressed.
Figure II shows one way in which a governor may be applied. H is a sleeve
sliding on the outside of the valve cylinder B. It is connected by a spindle passing
through a gland in the top of the steam chest with any suitable form of governor
capable of moving it upwards or downwards, so as to contract and enlarge the
ports E as required. It is obvious that this sleeve may be actuated by hand if
desired.
Figure III shows an engine with a gland and a moveable cylinder substituted
for the valve piston and cylinder. Jis the moveable cylinder, attached to the
steam piston by any suitable means, working through a gland K in the cylinder
cover, which serves to separate the steam chest from the cylinder. Steam is
admitted through the ports L in the moveable cylinder and is cut off by their
passing out of the steam chest into the gland K. If it be desired to apply a
governor the gland K may be made moveable under the influence of the governor
to cut off the steam earlier or later.
Figures IV and V show two arrangements in which the steam after leaving the
cylinder passes into a transfer space before being exhausted or otherwise dealt with.
In Figure IV there is at the lower end of the steam cylinder an extension N
containing a valve cylinder O which has near its lower end a ring of ports P. The
interior of this valve cylinder is in communication with the atmosphere or condenser.
Its top is closed by the piston valve M on the piston rod which works up and down
within it over the ports P, the arrangements being such that communication between
the exterior and interior of the valve cylinder is closed during the period that the
ports F in the steam cylinder are open, so that the atmosphere or condenser and the
working end of the steam cylinder are never placed in direct communication with
one another.
"
Figure V shows another method of obtaining the same result. Instead of the
fixed cylinder and the piston valve, a moveable cylinder Q is used attached to the
piston in any suitable manner and working through the gland S. in the lower cover
of the steam cylinder. The lower end of the moveable cylinder is open and communi-
cates with the atmosphere or condenser. Near the upper end are ports R, putting
the lower end of the cylinder, and the atmosphere or condenser in communication
with one another, and so placed that by their entry into the gland S, they cut off
this communication during the period that the ports F in the steam cylinder are
open, as in the former case.
Figure VI shows the arrangement as applied to a compound engine. The
means employed for admitting and distributing steam, are the same as in the simple
engine, and the exhaust may be regulated by one or other of the methods already
described.
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. An engine having two pistons rigidly connected together upon one rod,
working in cylinders, the one piston controlling the supply of fluid to the second, 5
and the other its escape to the atmosphere or condenser, each by alternately covering

page_text: and uncovering ports in the circumference of the cylinder in which it works,.
substantially as described.
2. An engine having a piston with a moveable hollow cylinder rigidly attached
to it, such cylinder having ports in its circumference which control the supply of
fluid to the working cylinder by alternately passing into and out of the supply
reservoir or steam chest, through a gland in the cover of the working cylinder,
and the piston regulating the escape of the fluid to the atmosphere or condenser by
alternately covering and uncovering ports in the circumference of the working
cylinder.
3. An engine having two pistons upon one rod, working in cylinders, sub-
stantially as described and a sleeve sliding on the outside of the supplying
cylinder, moved by any convenient means, and so controlling the admission of Huid
to such cylinder.
4. An engine having a driving piston, and a piston valve upon one rod, the
whole so arranged that during a portion of the return stroke fluid which has
operated against the piston upon one side, is transferred to the other side into a
closed chamber, and is then by the movement of the valve permitted to pass away
substantially as described.
5. An engine having a piston and a moveable cylinder attached to it, with ports
in it working through a gland in the bottom of the working cylinder, the whole so
arranged that during a portion of the return stroke fluid, which has operated against
the piston upon one side is transferred to the other side into a closed chamber and is
then by the movement of the valve permitted to pass away, substantially as
described.
6. An engine having two or more working pistons upon one rod, working in high
and low pressure cylinders, such pistons having attached to them supplementary
pistons or hollow moveable cylinders substantially as described.
Dated this 20th day of June 1893.
CARPMAEL & Co.,
Agents for the Applicant.