IMPROVEMENTS IN HIGH-SPEED ENGINES
Year: 1882

page_text: LETTERS PATENT to Peter William Willans of Thames Ditton in the County
of Surrey and Mark Heaton Robinson of Hampton Wick in the County of
Middlesex for an Invention of IMPROVEMENTS IN HIGH-SPEED ENGINES
"
PROVISIONAL SPECIFICATION left by the said Peter William Willans and
Mark Heaton Robinson at the Office of the Commissioners of Patents on the
14th October 1882.
PETER WILLIAM WILLANS of Thames Ditton in the County of Surrey and
MARK HEATON ROBINSON of Hampton Wick in the *County of Middlesex.
"IMPROVEMENTS IN HIGH SPEED ENGINES "
In high speed engines where the ordinary.compression of the steam in the
cylinder itself during the latter part of the return stroke of the piston, cannot be
advantageously used for checking the momentum of the piston and parts moving
to and fro therewith or is insufficient to check it we use an independent cushion or
buffer for the purpose.
This buffer consists of a ram or piston rigidly connected with the reciprocating
parts of the engine.
This ram or piston works in a cylinder which at one part of the stroke is in
communication with the atmosphere or any other elastic fluid (such as steam)
which may be employed as a cushioning medium.
At a certain part of the stroke of the ram or piston this way of communication
is closed, and the ram compresses the air or other fluid contained in the cylinder
until it reaches the end of its stroke.
We so arrange the capacity of this cylinder and the clearance provided between
the end of the cylinder and the piston or ram at the end of the stroke that by the
time the ram or piston has reached the end of its stroke the pressure of air or
other fluid has increased so much as to check to the desired extent the momentum
of the moving parts.

page_text: The power which is required to check their momentum is thus stored in the
compressed air or other fluid and given out again on the return stroke of the
piston.
The cylinder communicates with the atmosphere or reservoir of steam or other
fluid at some portion of each stroke so that any leak past the ram or otherwise is
made good. If the ram and cylinder be made perfectly air tight this opening will
not in all cases be necessary.
The volume into which the air or other fluid is' compressed at the end of the
stroke may be regulated by making the end of the cylinder to communicate with
a small chamber the internal capacity of which can be increased or diminished
by screwing more or less into it a screw plug or by providing the end or ends
of the cylinder itself with a screw plug which can be screwed more or less into
the cyliniler so as to bring it nearer to or further from the piston or ram at tho
ends of its travel.
With a single acting engine a single acting ram acting as above described is
used it may be a ram acting in a small cylinder at either end of the steam cylinder
and on the same piston rod as the piston of this cylinder or if a piston in the
form of a ram is working in the steam cylinder an enlargement on the outer end
of the ram may work in an enlargement of the cylinder the annular spaco
between this enlargement and the ram of the steam cylinder forming the air
compressing chamber.
In a double acting engine a double acting buffer would be used-consisting of a
piston or plunger on a continuation of the piston rod of the steam cylinder working
to and fro in a cylinder the clearance at the ends of which at the ends of the stroke
can be controlled as herein before described.
Instead of controlling the cushioning at the end of the stroke by controlling
the space capacity into which the air or other controlling fluid is compressed
at the end of the stroke the cushioning might be controlled by varying the
point in the stroke at which the air or fluid admission into the cylinder is
closed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter William Willans and Mark Heaton Robinson in the Great
Seal Patent Office on the 14th April 1883.
"
PETER WILLIAM WILLANS of Thames Ditton in the County of Surrey and
MARK HEATON ROBINSON of Hampton Wick in the County of Middlesex.
IMPROVEMENTS IN HIGH SPEED ENGINES
"
In high speed engines where the ordinary compression of the steam in the
cylinder itself during the latter part of the return stroke of the piston, cannot be
advantageously used for checking the momentum of the piston and parts moving
to and fro therewith or is insufficient to check it we use an independent cushion or
buffer for the purpose.
. This buffer consists of a ram or piston rigidly connected with the reciprocating
parts of the engine.
This ram or piston works in a cylinder which at one part of the stroke is in
communication with the atmosphere or any other elastic fluid (such as steam)
which may be employed as a cushioning medium.
At a certain part of the stroke of the ram or piston this way of communication
is closed and the ram compresses the air or other fluid contained in the cylinder
until it reaches the end of its stroke.
We so arrange the capacity of this cylinder and the clearance provided between
the end of the cylinder and the piston or ram at the end of the stroke that by the
time the ram or piston has reached the end of its stroke the pressure of air or
other fluid has increased so much as to check to the desired extent the momentum
of the moving parts.
The power which is required to check their momentum is thus stored in the
compressed air or other fluid and given out again on the return stroke of the
piston.
The cylinder communicates with the atmosphere or reservoir of steam or other
Buid at some portion of each stroke so that any leak past the ram or otherwise is
made good. If the ram and cylinder could be made perfectly air tight this opening
would not be necessary.
The volume into which the air or other fluid is compressed at the end of the
stroke may be regulated by making the end of the cylinder to communicate with
a small chamber, the internal capacity of which can be increased or diminished.by.
screwing more or less into it a screw plug or by providing the end or ends of the
cylinder itself with a screw plug which can be screwed more or less into the
cylinder so as to bring it nearer to or further from the piston or ram at the ends
of its travel..
With a single acting engine a single acting ram acting as above described is
used-it may be a ram acting in a small cylinder at either end of the steam cylinder
and on the same piston rod as the piston of this cylinder or if a piston in the
form of a ram is working in the steam cylinder an enlargement on the outer end
of the ram may work in an enlargement of the cylinder-the annular space
between this enlargement and the ram of the steam cylinder forming, the air,
compressing chamber. Or this may be reversed and the cylinder be for air
compressing and the annular space for steam.
In a double acting engine a double acting buffer would be used-consisting of
a piston or plunger on a continuation of the piston rod of the steam cylinder
working to and fro in a cylinder the clearance at the ends of which at the ends
of the stroke can be controlled as herein before described.
i

page_text: Instead of controlling the cushioning at the end of the stroke by controlling
the space capacity into which the air or other controlling fluid is compressed
at the end of the stroke the cushioning might be controlled by varying the
point in the stroke at which the air or fluid admission. into the cylinder is
closed.
Having thus described the nature of our invention we will proceed to describe
Call a minuse of narforming the same
DESCRIPTION OF THE DRAWINUS.
Figure 1 shews a vertical section through the cylinder of a single acting quick
running steam engine. The engine may be formed with only a single cylinder as
shown in the Drawing or there may be any desired number of such cylinders with
their pistons working on to the one crank shaft as in steam engines heretofore
commonly constructed by us and by others.
Each cylinder of the engine we provide with an air cushion or buffer in the
manner above explained.
A is the steam cylinder, B the piston. C the piston rod having at its end a
second piston or plunger D to which is jointed a connecting rod that works. on to
a crank on the crank shaft E. The second piston D works to and fro in a
cylinder F which not only serves as a guide for it but also as an air compressing
cylinder to serve as a buffer for checking the momentum of the piston at the end
of its backward or return stroke.
The lower end of the cylinder A opens into a chamber which communicates
with the condenser or exhaust passage. The piston rod O passes through this
chamber and through a stufling box in a cover H which closes the top of the lower
cylinder F from the chamber G. The cover H is shown to be made hollow and
The hollow
with two separate stufling boxes for the piston rod to pass through.
interior of the cover H is by a passage I open to the atmosphere in order that if on
the return stroke of the piston any air under pressure should leak past the lower
stuffing box into the hollow interior of the cover it may not force its way past the
upper stuffing box and so find its way to the condenser. J is a cover enclosing the
cylinder F and at a distance from it. A small air passage is formed at any
convenient point through this cover. K. K are openings by which air can enter
the cylinder F when the piston is at the lower end of its stroke. The upper end of
the cylinder F is by a passage L put into communication with a closed air vessel M
provided with an air cock N. O is a valve in the passage L which prevents the
return of air from the air vessel Minto the cylinder F. The air vessel and air cock
are to facilitate the starting of the engine. When starting the engine the air cock
is opened and steam admitted to the top of the cylinder and the piston thereby
caused to make its stroke The momentum thereby imparted to the fly wheel on
the crank shaft causes the piston to make its return stroke the air in the upper
part of the cylinder F is then somewhat compressed and forced into the air
vessel M. and so at each return stroke of the piston n certain amount of compressed
air is driven into the air vessel. As the engine gains in speed the air cock N is
closed gradually and the pressure in the air vessel consequently rises. When it
has been entirely closed the pressure in the air vessel rises until the air contained
in it is at a pressure equal to the pressure of air in the cylinder F at the end of
each-return-stroke. No more air then passes into the air yessol and it so goes out
of action. At each forward stroke of the piston the connecting rod thrusts against
the crank pin. On the return-stroke the pin thrusts against the rod to force the
piston back. As it does so it compresses air behind the piston D so that at the end
of the return stroke this compressed air acting upon the piston D may keep the
connecting rod still thrusting, against the crank pin although the momentum of the
moving parts would otherwise separate them and so long as the engine runs at a
uniform speed no strap would be required at the end of the connecting rod to

page_text: embrace the crank pin. The strap is only of service when starting or stopping the
engine or in the event of racing. P is an air inlet valve by which air is admitted
freely to the cylinder F at all times during the forward stroke should the pressure
in this cylinder get below atmosphere pressure If the engine is a three cylinder
engine no fly wheel is needed.
In the Drawing we have not thought it necessary to show the valves for
admitting steam to the top of the cylinder A or allowing steam to pass from this
cylinder to the exhaust as these valves may be of any ordinary construction. The
position of the air openings K in the cylinder F will depend upon the speed at
which the engine is required to run the quicker the speed the nearer would the
openings K have to be to the lower end of the cylinder or the smaller the clearance
at the end of stroke. Holes closed by plugs might be provided in the cylinder at
different heights to allow of the exit of air from the cylinder F being closed either
at an earlier or later portion of the return stroke according to the speed at which
the engine is required to run.
Instead of providing for closing the exit of air from the cylinder F at an earlier
or later period of the return stroke as above described the volume into which the
air is compressed at the end of the return stroke may as above stated be regulated
by making the end of the cylinder F to communicate as shewn in the diagram
view Figure 2 with a small chamber R the internal capacity of which can be
increased or diminished. In the diagram the capacity of the chamber R is shewn
to be regulated by screwing more or less into its end a long screw but other
arrangements might be adapted for increasing or diminishing. the capacity of the
chamber R.
Instead of the air cylinder F being between the steam cylinder and the crank
shaft it might be at the opposite end of the steam cylinder, a continuation of the
piston rod being then carried through the end cover of the cylinder A. Figure 3
shews a diagram view of another form in which the single acting engine may be
arranged In this case a ram A' is made to work into the cylinder A and an
enlargement B' on the outer end of the ram is made. to work in an enlargement B
of the cylinder. The forward stroke may be made by steam admitted either to
the cylinder A or to the annular space B. If it is effected by steam admitted
to A then the annular space B forms the air buffer on the return stroke and air is
admitted to the space at the commencement of the return stroke through
openings E. If on the other hand the forward stroke is. effected by steam
admitted to the annular space B then the cylinder A forms the air buffer
and air is admitted to it at the commencement of the return stroke through
openings F.
In double acting engines the air buffer has also to be double acting. Figure 4
shews a diagram view of a double acting steam cylinder and double acting air
buffer used in connection therewith. A is the steam cylinder A¹ its piston-the
piston rod is prolonged and carries a plunger B' which works to and fro in the air
cylinder B. Air is admitted to the centre of the cylinder B through openings E.
The plunger B is somewhat shorter than the length of the stroke of the piston
consequently at the end of each stroke air is admitted to one or other end of the
cylinder. The diagram shews that the volume into which the air is compressed at
the end of each stroke may be adjusted by setting the end covers nearer to or
further away from one another. The diagram shows the end covers screwing into
the ends of the cylinders to allow of this being done. Or in place of this rings or
washers might be interposed between the covers and the ends of the cylinder the
covers could then be bolted on in the ordinary way. The details herein before
given with reference to the position of the air openings and the other details
described with reference to single acting engines are all applicable to double acting
engines.
Having thus described the nature of our invention and the manner of performing
the same we would have it understood that we claim :-
First. The employment in combination with single acting cylinders of steam

page_text: engines of an elastic buffer of air or other elastic fluid in a separate cylinder to
arrest the momentum of the reciprocating parts of the engine in the return stroke
substantially as herein before described.
Second. The employment in combination with the steam cylinders of steam
engines of elastic buffers of air or other fluid compressed at the end of each stroke
in an additional cylinder for arresting the momentum of the reciprocating parts
substantially as described.
Third. The means substantially as herein before described for adjusting the
volume into which the air or other fluid of the elastic buffer is compressed on the
return stroke:
Fourth. The means substantially as herein before described for facilitating the
starting of the engine when elastic buffers of air or other elastic fluid are employed
to arrest the momentum of the reciprocating parts.
Fifth. The combined arrangements of steam engine substantially as herein before
described.
In witness whereof I the said Peter William Willans have hereunto set my
hand and seal this thirteenth day of April in the year of our Lord One
thousand eight hundred and eighty three.
P W WILLANS (L.S.).