IMPROVEMENTS IN MOTIVE-POWER ENGINES
Year: 1867

page_text: LETTERS PATENT to John Weems, of Johnstone, and Thomas Robertson,
of Kennishead, both in the County of Renfrew, North Britain, for the
Invention of "IMPROVEMENTS IN MOTIVE-POWER ENGINES."
Sealed the 20th August 1867, and dated the 21st February 1867.
PROVISIONAL SPECIFICATION left by the said John Weems and
Thomas Robertson at the Office of the Commissioners of Patents, with
their Petition, on the 21st February 1867.
We, JOHN WEEMS, of Johnstone, and THOMAS ROBERTSON, of Kennishead,
both in the County of Renfrew, North Britain, do hereby declare the nature
of the said Invention for IMPROVEMENTS IN MOTIVE-POWER ENGINES," to be
as follows, that is to say:
This Invention, which relates to a special construction and arrangement of
mechanism or apparatus from which motive power is or may be obtained, is
based upon an Invention for "Improvements in Obtaining and Applying Motive
Power, for which Letters Patent were granted unto John Weems, bearing
date the 2nd day of October 1852, and numbered 188.
7
The engine, means, or apparatus comprised under the present Invention is
that which has resulted from considerable experiment with and alterations upon
the former Invention, and it now consists of an annular chamber in which
weighted piston or body of the same shape as and capable of moving round or
partly round inside the annular chamber is placed; arms project from the inuer

page_text: side of the annular chamber and unite into a steam passage at the centre; two
of these arms extend to and are coupled to the steam and exhaust valve boxes.
The passage at the centre of the apparatus is divided into four passages, two of
which allow the steam to be brought in from an adjacent boiler, the other
two being connected with the exhaust port, thus permitting the used steam
to escape into the atmosphere. In setting the engine to work steam is
admitted through one of the central steam passages, along which it passes to
one of the tubular arms, herein-before referred to, through the steam valve
into the annular space; the steam then acts between a moveable trap door
which now stands up and fills the annular chamber steam-tight; this trap
door acting as an abutment, from which the steam propells the weighted piston,
and causes the revolution of the engine. As soon as the apparatus has been
impelled round half a revolution a steam valve and trap door in the opposite
'side of the annular chamber are opened up; the trap door through which
the steam first passed into the chamber now becoming shut by means of a
spring situated at an angle on the other end of the piston forcing the door
down very gradually and with little noise as the apparatus revolves; just
before the trap door is shut the inclined end of the piston passes over and
shuts down a short lever attached to a connecting rod for shutting the steam
valve opening the exhaust port, at the same time opening the second steam
valve, on the opposite side or end of the apparatus; the steam and exhaust
valves are of the equilibrium class. To prevent noise from occurring by the
opening of the trap door, one or both ends of the weighted piston are provided
with curved or inclined planes, so that the trap door may open very gradually.
The sides of the trap doors are provided with metallic or other packing to
prevent the steam leaking through; one or both ends of the weighted piston
are also provided with metallic or other packing to keep it steam-tight. The
trap doors and valve levers may be actuated by the pressure of steam alone,
or they may have springs, levers, or other suitable contrivance for actuating
them. The annular chamber is provided with valves or cocks, or other similar
apparatus for the purpose of relieving the chamber of the reaction of the
steam and cold water.
It is further to be understood that the motive-power engines comprised
under the present Invention may be worked on the condensing principle by
allowing the exhaust steam to be condensed by an air pump and condenser in
the usual manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Weems and Thomas Robertson in the Great Seal
Patent Office on the 21st August 1867:
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
WEEMS, of Johnstone, and THOMAS ROBERTSON, of Kennishead, both in the
County of Renfrew, North Britain, send greeting.
с
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of February, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year, of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
John Weems and Thomas Robertson, Her special license that we, the said
John Weems and Thomas Robertson, our executors, administrators, and
assigns, or such others as we, the said John Weems and Thomas Robertson,
our executors, administrators, or assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN MOTIVE-POWER ENGINES,"
upon the condition (amongst others) that we, the said John Weems and
Thomas Robertson, by an instrument in writing under our hands and seals,
should particularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said John Weems and Thomas Robertson,
do hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say :-
.
Our said Invention, which relates to a special construction and arrangement
of mechanism or apparatus from which motive power is or may be obtained, is
based upon an Invention for "Improvements in Obtaining and Applying Motive
Power," for which Letters Patent were granted unto John Weems, dated the
Second day of October 1852, and numbered 188.
The engine or apparatus comprised under the present Invention is that
which has resulted from considerable experiment with and alterations upon
the former Invention, and it now consists of an annular chamber. in which a
weighted piston or body of the same shape as and capable of moving round or

page_text: partly round inside the annular chamber is placed. Arms project from the
inner side of the annular chamber and unite into a steam passage at the
centre; two of these arms extend to and are coupled to the steam and exhaust
_valve boxes. The passage at the centre of the apparatus is divided into four
ways or ducts, two of which allow the steam to be brought in from an adjacent
'boiler, the other two being connected with the exhaust port, thus permitting
the used steam to escape into the atmosphere. In setting the engine to work
steam is admitted through one of the central steam passages, along which it
passes to one of the tubular arms herein-before referred to, through the steam
valve into the annular space; the steam then acts between a moveable trap
döör, which now stands up and fits the annular chamber steam-tight, the trap
door acting as an abutment from which the steam propells the weighted piston
and causes the revolution of the engine. As soon as the apparatus has been
impelled round half a revolution à steam valve and trap door in the opposite
side of the annular chamber are opened up, the trap door through which the
steam first passes into the chamber now becoming shut by means of a spring
or inclined plane, situated at an angle on the other end of the piston, forcing the
door down very gradually and with little noise as the apparatus revolves. Just
before the trap door is shut the inclined end of the piston passes over and shuts
down a short lever attached to a connecting rod for shutting the steam valve
<opening the exhaust port, at the same time opening the second steam valve on
the opposite side or end of the apparatus. The steam and exhaust valves are of
the equilibrium class. To prevent noise from occurring by the opening of the
trap door one or both ends of the weighted piston are provided with curved.or
inclined planes so that the trap door may open very gradually. The sides of
<the trap doors are provided with metallic or other packing to prevent the steam
leaking through. One or both ends of the weighted piston are also provided
with metallic or other packing to keep it steam-tight. The trap doors and
valve levers may be actuated by the pressure of the steam alone or they may
have springs, levers, or other similar contrivance for actuating them. The
annular chamber is provided with valves or cocks or other similar apparatus
for the purpose of relieving the chamber of the reaction between the steam
and cold water.
+
It is further to be understood that the motive-power engines comprised
under the present Invention may be worked on the condensing principle by
allowing the exhaust steam to be condensed by an air pump and condenser in
the usual manner.
And in order that our said Invention may be properly understood we shall
now proceed more particularly to set, forth the system, mode, or manner in or

page_text: under, which the same is or may be used or practically carried into effect,
reference being bad, for the sake of more complete elucidation, to the several
Figures upon the explanatory Sheet of Drawings which we have hereunto
appended, that is to say :-
;
Figure 1 is a longitudinal section of an engine constructed in accordance
with our Invention, and Figure 2 is a transverse section on the line A, A,
Figure 1.
The engine consists of an annular ring B, Figures 1 and 2, in which a
weighted piston C is free to move by the reaction of the steam against it, as
herein-after described; D, D, are arms cast on the inner side of the annular
rings; D¹, D', the valve casing containing the equilibrium valves marked V, VI,
Figures 1 and 2; E; the boss, the arms of which contain the steam passages
through which the steam is conveyed to the valves; this central part is firmly
held to the outer parts of the engine by bolts passing through flanches C; F, F¹,
Figure 2, are the axes upon which the annular ring revolves, which in the case
of a traction engine are carried in the framing, or in the case of a marine or
stationary engine in suitable fixed bearings; through these pieces F the steam
passes into the engine, and through F¹ the exhaust steam escapes into the
atmosphere, the exhaust pipes G, G¹, Figures 1 and 2, being connected
thereto, or it may be taken in the usual manner to a condenser, in which case
the engine would be worked as a condensing engine; H, H', are trap doors
forming abutments against which the steam acts, the working of which is
herein-after set forth; J, J, Figure 1, are spiral springs on one side of the
engine, one of the ends of the springs being connected with the arms of the
central boss which has snugs formed on it for receiving and holding the springs,
the other end of the springs being connected to the levers K, K³, which
actuate the trap doors; L, L, are similar springs for opening the valves
through the intervention of the levers M, M' and N, N1, the length of these
springs being regulated by the nuts 0, 0¹. Into the trap doors H, H',
tongues of brass or other suitable material are inserted, these again being
kept in position by springs fastened to the trap doors, so that when the trap
doors are projected forwards or raised by the springs J, J', out of the recesses
into which they are pressed by the piston the tongue strikes the side of the
annular chamber, and the springs on the under side are forced backwards, and
thereby act as buffers to modify the force of impact, so that the surface of the
annular ring will not be indented.
?
In setting the engine to work steam is admitted through the axis F,
Figure 2, filling.the steam passages P, Figures 1 and 2; in the present position
of the engine the steam is being admitted to the annular ring by the port R,

page_text: Figure 1. The exhaust port T is open and in communication with the pipe G
through the passage, also marked G, Figures 1 and 2; meanwhile the trap
door H is kept out by the action of the spring J, thus cutting off communi-
cation between the steam and the inclined or tapered end of the piston Q,
Figure 1. The steam being confined between the trap door H and the opposite
end of the piston Q¹, which being rendered steam-tight by the application of
flexible metallic packing forces the piston round in the direction indicated by
the arrow; the inclined end of the piston Q is thus made to gradually push
down the arm of the lever N which actuates the lever N₁, causing the cam or
tooth fixed on the same rocking shaft to push along the valve, thus cutting off
all communication between the annular rings and the steam and exhaust
passages at that side of the ring. Just as the lever N is being pressed down
by the end of the piston Q the trap door H, Figure 1, is set free, the opposite
end of the piston Q' having passed beyond it; it is now projected outwards
by the pull produced by the spiral spring J' acting on the lever. The equi-
librium steam valve on this side has hitherto been kept closed by means of
the lever W, Figure 1, preventing the inward movement of the lever M' on
account of the pressure of the stud S which presses on the lever W; as soon
as this lever W, however, is moved by the action of the spring J' on the
lever W' the spring L' acting on the levers M and M' causes the cam X¹ fixed
on the same rocking shaft as the lever M to push along the valve, thus
opening the connection between the annular ring and the steam passage P on
one side by the port R¹ of the trap door, and by the exhaust port T' and
pipe G on the other side, by being connected with the axes F¹. The ring now
moves through half a revolution and the trap doors are again shut and opened
by coming into and leaving contact with the piston C¹.
It is to be understood that a peculiar feature of the engine herein-before
described and shown on the annexed Sheet of Drawings is that whilst working
under a constant load the weight C is stationary and the annular cylinder
revolves round upon the weight. Should it happen that the load is a variable
one the weight rises or falls proportionately with the load, so that the power
of the engine is partly ascertained by the perpendicular distance of the centre
of gravity of the weight from the axis of the engine. It is to be understood
that in place of steam the engine may be driven by means of compressed air,
water, or by a gas.
It must not escape notice that a very important part of the engine we have
now specified is that the force of the motive agent is not employed to drive
mechanism of a secondary character in actuating the engine, but that all the
moving parts are comprised within the circle of revolution of the engine itself,

page_text: whereby additional mechanical effect is gained. In place of using a cam or
tooth X for opening and closing the equilibrium valves they may be actuated
by a pinion fastened on the shaft gearing into a rack on the under side of the
valves, so that as the pinion is partly revolved by means of the lever M the
equilibrium valves are moved so as to open or close the steam and exhaust
ports.
Relief valves v, one of which is shown in enlarged section at Figure 3, are
employed, so that in the event of the steam condensing the atmospheric
pressure acting on them opens them inwards, at the same time allowing the
water of condensation to escape..
;
In the event of the steam on starting the engine being let too violently into
the annular space the weight or piston C may be suddenly elevated to an
undue extent, in which case it might fall down and strike a trap door, in
order, therefore, to prevent injury being done to the door by the force of the
blow corrugated springs w are fitted to the butt end of the piston or weight to
cushion the blow, and instead of springs india-rubber or other elastic medium
may be used.
In conclusion we wish it to be understood that engines constructed as
herein-before described may be used for stationary, marine, and locomotive
purposes, for traction on common roads, and agricultural purposes.
Having now described and particularly ascertained the nature of our said
Invention, and the manner in or under which the same is or may be used or
practically carried into effect, we would observe in conclusion that what we
consider novel and original and therefore claim as the Invention secured to us
by the herein-before in part recited Letters Patent is,-
First, the general arrangement and construction of machinery, apparatus,
or means for obtaining and applying motive power, as herein-before described,
or any mere modification thereof.
Second, the system or mode of obtaining motive power by a hollow annular
chamber revolving round a weight by means of the force of a motive agent,
as herein-before described, or any mere modification thereof.
Third, the system or mode of driving motive-power engines by the pressure
being directly used in place of being applied to actuate secondary mechanism,
as herein-before described, or any mere modification thereof.
Fourth, the system or mode of opening and closing the valves for the
admission and exhaust of the steam means of the piston or weight being
arranged to act upon springs, as herein-before described, or any mere modi-
fication thereof.
Fifth, the use and application of relief valves to prevent the reaction

page_text: between the condensed water and the steam, and for releasing the water, as
herein-before described, or any mere modification thereof.
Sixth, the application of an inclined end to the piston or weight, so as to
gradually shut the trap doors, as herein-before described.
:
Seventh, the application of springs to the under side of the trap doors, so
as to cushion or diminish the force of the blow as the trap doors open, as
herein-before described.
Eighth, the use and application of packing to the piston or weight, as
herein-before described.
Ninth, the application of springs to the butt end of the piston or weight so
as to cushion the force of the blow on the trap door in the event of the weight
or piston falling down against it, as herein-before described.
In witness whereof, we, the said John Weems and Thomas Robertson,
have hereunto set our hands and seals, this Seventeenth day of August,
One thousand eight hundred and sixty-seven.
Witness,
ST. JOHN VINCENT DAY, C. E.,
Patent Offices,
166, Buchanan Street,
Glasgow:
(LS.)
JOHN WEEMS.
THO. ROBERTSON. (L.S.)