IMPROVEMENTS IN MOTOR ENGINES WORKED BY COMPRESSED AIR OR OTHER ELASTIC FLUID UNDER HIGH PRESSURE
Year: 1876

page_text: LETTERS PATENT to Frederick Edward Blackett Beaumont, of No. 2, West-
minster Chambers, Victoria Street, in the County of Middlesex, for the Inven-
tion of "IMPROVEMENTS IN MOTOR ENGINES WORKED BY COMPRESSED AIR OR
OTHER ELASTIC FLUID UNDER HIGH PRESSURE."
PROVISIONAL SPECIFICATION left by the said Frederick Edward Blackett
Beaumont at the Office of the Commissioners of Patents, on the 1st January
1876.
MOTOR
FREDERICK EDWARD BLACKETT BEAUMONT, of No. 2, Westminster Chambers,
Victoria Street, in the County of Middlesex. "IMPROVEMENTS IN
ENGINES WORKED BY COMPRESSED AIR OR OTHER ELASTIC FLUID UNDER HIGH
PRESSURE."
My Invention relates to motor engines worked by compressed air or other fluid
under high pressure supplied to them from a charged reservoir, and consists in an
arrangement and construction of such engines whereby the expansive force of the
working fluid can be largely utilised, and the power developed can be increased or
diminished as required, or can be nearly equalised, notwithstanding considerable
reduction of pressure in the reservoir as its contents are gradually worked out.
I arrange side by side three or more single acting cylinders of different areas, the
second having an area considerably greater than the first, the third having an area
greater than the second, and so on, the last of the series having the greatest area.
Along the closed ends of these cylinders there is a pipe communicating with the
charged reservoir and having branches to the several cylinders, these branches
being provided with slide or other valves whereby they can be closed or opened at
pleasure, for which purpose I prefer to employ a single slide covering the openings
of all the branches so that when it is moved a certain distance it opens the branch
to the first cylinder, when farther moved it opens also the branch to the second
cylinder, and so on successively.
The several cylinders are also provided with rotatory or other slides or valves,
whereby fluid under pressure is alternately admitted to and discharged from them
in ordinary steam engines, the discharge from the first cylinder supplying the

page_text: second, that from the second supplying the third, and so on to the last cylinder,
which discharges into the atmosphere.
The pistons or plungers of the several cylinders are connected to cranks on one
shaft, and these cranks may be set each opposite to the next in order, or nearly so,
in which case the discharge from the one cylinder may directly supply the next in
order, or the cranks may be set at different angles on the shaft, in which case each
cylinder discharges into a reservoir, from which the next cylinder in order receives
its supply. At first starting with a fully charged reservoir the first branch pipe
only is opened, whereby the working fluid is admitted to act with its full pressure
only on the first or smallest piston, the other pistons being successively acted on
by it after its successive expansions into each increased capacity of cylinder. If
however the power should require to be temporarily increased then the branch to
the second cylinder may be also opened wholly or partially, the second piston being
thus acted on either by the full pressure or part of the full pressure, and the
succeeding pistons being subjected to a pressure proportionally increased. And in
like manner when the pressure in the reservoir has been reduced by the partial
working out of its contents in supplying the first cylinder the branch to the
second cylinder can be wholly or partially opened. After a still farther reduction
of pressure in the reservoir the branch to the third cylinder may be opened, and so
on until the last cylinder has been put in direct communication with the reservoir.
By this arrangement the reduced pressure of the working fluid being made to act
on an increased area of piston the working power may be rendered nearly uniform
notwithstanding the variation of pressure in the reservoir.
By adopting single acting cylinders there is always a thrusting strain on the
connecting rods, and thus the shocks usually attending reversals of strain are
avoided and the mechanism is greatly simplified.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederick Edward Blackett Beaumont in the Great Seal Patent Office
on the 26th June 1876.
FREDERICK EDWARD BLACKETT BEAUMONT, of No. 2, Westminster Chambers,
Victoria Street, Westminster, in the County of Middlesex. "IMPROVEMENTS IN
MOTOR ENGINES WORKED BY COMPRESSED AIR OR OTHER ELASTIC FLUID UNDER
HIGH PRESSURE."
My Invention relates to motor engines worked by compressed air or other fluid
under high pressure supplied to them from a charged reservoir, and consists in an
arrangement and construction of such engines whereby the expansive force of the
working fluid can be largely utilised, and the power developed can be increased or
-diminished as required, or can be nearly equalised, notwithstanding considerable
reduction of pressure in the reservoir as its contents are gradually worked out.
I arrange side by side three or more single acting cylinders of different areas, the
second having an area considerably greater than the first, the third having an area
greater than the second, and so on, the last of the series having the greatest area.
Along the closed ends of these cylinders there is a pipe communicating with the
charged reservoir and having branches to the several cylinders, these branches
being provided with slide or other valves whereby they can be closed or opened at
pleasure, for which purpose I prefer to employ a single slide covering the openings
of all the branches, so that when it is moved a certain distance it opens the branch
to the first cylinder, when farther moved it opens also the branch to the second
cylinder, and so on successively.
The several cylinders are also provided with rotating or other slides or valves
whereby fluid under pressure is alternately admitted to and discharged from them
as in ordinary steam engines, the discharge from the first cylinder supplying the

page_text: second, that from the second supplying the third, and so on to the last cylinder;
which discharges into the atmosphere.
'
The pistons or plungers of the several cylinders are connected to cranks on one'
shaft, and these cranks may be set each opposite to the next in order, or nearly so,
in which case the discharge from the one cylinder may directly supply the next in
order, or the cranks may be set at different angles on the shaft, in which case each
cylinder discharges into a reservoir, from which the next cylinder in order receives
its supply. At first starting with a fully charged reservoir the first branch pipe
only is opened, whereby the working fluid is admitted to act with its full pressure
only on the first or smallest piston, the other pistons being successively acted on
by it after its successive expansions into each increased capacity of cylinder. If
however the power should require to be temporarily increased then the branch to
the second cylinder may be also opened wholly or partially, the second piston
being thus acted on either by the full pressure or part of the full pressure, and the
succeeding pistons being subjected to a pressure proportionally increased.
in like manner when the pressure in the reservoir has been reduced by the
partial working out of its contents in supplying the first cylinder the branch
to the second cylinder can be wholly or partially opened. After a still further
reduction of pressure in the reservoir the branch to the third cylinder may be
opened, and so on until the last cylinder has been put in direct communication
with the reservoir. By this arrangement the reduced pressure of the working
fluid being made to act on an increased area of piston the working power may
be rendered nearly uniform notwithstanding the variation of pressure in the
reservoir.
And
By adopting single acting cylinders there is always a thrusting strain on the
connecting rods, and thus the shocks usually attending reversals of strain are
avoided, and the mechanism is greatly simplified.
DESCRIPTION OF THE DRAWINGS,
Fig. 1 represents a sectional plan and Fig. 2 a transverse section on the line X, X,
of Fig. 1 of a motor engine, according to my Invention, to be worked by air or
other elastic fluid condensed to a high degree of pressure in a reservoir.
In the engine shewn in Fig. 1 there are five working cylinders A¹, A², A³, A¹,
and A5, but there might be a greater or less number; each of those cylinders is
made single acting, and is fitted to oscillate on a cylindrical block or trunnion B¹
to B³, in which are formed supply passages C¹ to C³, and discharge passages D¹
to D³, set at such an angle that each cylinder receives a supply of the working
fluid during a great part of the outstroke of its plunger, and that during a great
part of the instroke the fluid can escape from the cylinder by the discharge
passage D¹ to D³, which by a channel E¹ to E' communicates directly with the
supply passage of the cylinder next beyond it; the cranks F1 to F5 on the shaft S, S,
are set thereon so that each is opposite or nearly so to that next in order, and
thus when the plunger of one cylinder is making its instroke that of the next
cylinder is making its outstroke. The cylinders are made successively of greater
diameter, that is to say, A² is greater than A¹, As is greater than A², and so on, so
that the working fluid escaping from each during the instroke of its plunger
expands into the next cylinder, propelling its plunger, until after considerable
expansion it escapes from the last cylinder A5 by the passage Es. A pipe G com-
municating with the reservoir of working fluid is fitted with a set of slides H¹
to H³, all connected together by rods I so that they can be moved longitudinally
within the pipe G. In the position of the slides as shewn in Fig. 1 they cover all
of a set of lateral passages K¹ to K³, communicating respectively with the passages
of the successive cylinders, and in this condition the engine is stationary, no fluid
being supplied to work it. On moving the slides a little distance so that the part H¹
uncovers the passage K', but none of the other passages K³ to K³ are uncovered,

page_text: working fluid is supplied from the reservoir to the port C of the first cylinder A¹
only, and having caused the plunger of that cylinder to make its outstroke escapes
during the instroke by the passage D¹ to the channel E¹, by which it is led to the
supply port Cs of the second cylinder A³, causing its plunger to make an outstroke
while the plunger of A¹ is making its instroke. In like manner the fluid discharged
from A supplies the third cylinder A³, and so on, expanding by steps into the
successive cylinders, until after having done its work in the last cylinder it escapes
finally by the outlet E. When after a certain time of working the pressure of
fluid in the reservoir has become reduced the slides H are moved somewhat farther
until the second part H2 uncovers the passage K², the first passage K¹ remaining
open, but the other passages K³, K, and K remaining closed. The first cylinder A
is, thus rendered inoperative as the fluid merely flows into it during the outstroke,
and out of it during the instroke, but the second cylinder A now receives its
supply direct from the reservoir, and the successive cylinders after it work as
already described. Again, when the pressure in the reservoir is still farther
reduced the slides H are moved so that H³ uncovers K³, in which case both A¹ and
As are rendered inoperative, A³ receiving its supply direct from the reservoir. By
thus admitting the fluid to act on a larger area of plunger as its pressure is
diminished the working power of the compound engine may to a great extent be
equalised, while at the same time the expansive force of the condensed fluid is
Largely utilised.
I have shewn in the accompanying Drawings the several cylinders of the
oscillating kind with the cranks on which their plungers work opposite to each
other, or nearly so, alternately, this form of engine presenting several advantages
in cases where compactness and simplicity are of importance, as it enables me to
dispense with connecting rods and slide or other valves; with eccentrics for working
them, and to arrange the passages from each cylinder to the next. and put them
under the control of one set of valves in a simple manner. Moreover the cylinders
being single acting the strain on the plungers and bushes is always in one direction,
and thus prevents shock and noise in working. It may be readily understood
however that other forms of cylinders, such as double-acting cylinders with con-
necting rods and slides, could be used in the manner described, and that the
successive cranks could be set at other angles to each other, proper spaces being
provided in the passages from the several cylinders to the next in order to act as
intermediate reservoirs for the working fluid as in compound engines of ordinary
construction.
In applying a compound engine such as I have described to work a locomotive
for a tramway car or other vehicle, using compressed air as the working fluid, the
reservoir of air may conveniently consist of a number of tubes, all communicating
with the pipe G; also the shaft S. may be connected by suitable gear with the
driving, wheels, such gear including reversing bevil wheels, and clutch, such as are
often employed in planing machines, so that while the shaft S is always made to
revolve in one, direction the driving wheels may be driven in either direction as
required.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I hereby declare. that I make no general claim to the use
of successive cylinders, having successively increasing areas, whereby the expansion
of the elastic fluid can be utilised; but I claim,-
First. The method, substantially as herein described, of equalising the power of
an engine worked by elastic fluid condensed in a reservoir, and of utilising the
expansive power of the fluid by causing it to act successively in a number of
cylinders of successively, increasing areas, the supply passages of these cylinders
being placed under the control of a slide or valve whereby they can successively be
placed in direct communication with the reservoir.
Second: In a compound engine worked according to the method referred to in
the preceding claim, arranging the successive cylinders side by side with their

page_text: supply passages all opening to one pipe communicating with the reservoir of
working fluid, and governed by a slide fitted in the said pipe, substantially as
herein described.
In witness whereof, I, the said Frederick Edward Blackett Beaumont, have
hereunto set my hand and seal, this Twentieth day of June, in the year of
our Lord One thousand eight hundred and seventy-six.
FREDERICK EDWARD BLACKETT BEAUMONT. (L.B.)