IMPROVE- MENTS IN MEANS FOR REVERSING THE MOTION OF STEAM ENGINES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I GEORGE THOMPSON DICKINSON of the City and County of Newcastle upon
Tyne Gentleman do hereby declare the nature of said Invention for "IMPROVE-
MENTS IN MEANS FOR REVERSING THE MOTION OF STEAM ENGINES" to be as
follows:-
:-
My Invention has for its object to provide means whereby the motion of Steam
Engines can be reversed without the necessity for the complicated gear hitherto
provided for the purpose.
According to my Invention I make the slide valves to slide upon a moveable
slide face which in its turn can be moved upon the faceing of the steam chest the
passages through the said chest communicating with the cylinder are made of such
a width that the ports through the moveable slide face are opposite the said
passages into whichever position the moveable slide face may be brought.
The slides themselves are provided with what may be regarded as double sets of
ports or steam ways which as the slides are reciprocated are brought opposite the
ports in the moveable slide face and valve chest. These double ports or steam
ways in the slides are so arranged that when the moveable slide face is in one
position the ports or ways constituting the one set are in communication with the
cylinder through the passages on the said moveable face and the large passages in
the steam chest but when the moveable slide face is moved over into its other
position the entry for steam is reversed and the other ports or passages in the slide
which constitute the second set are in communication with the cylinder so that
steam is admitted in such manner as to reverse the Engine. I prefer to make the
steam inlets and the exhausts on opposite sides of the cylinder or cylinders and to
provide the inlet and exhaust each with separate valves arranged or described.
Where two or more cylinders are employed side by side I prefer to make the
moveable slide face by which the reversing action is obtained common to all the
cylinders and their valves so as to reverse them all at the same time.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.O.,
Agent for the said George Thompson Dickinson.

page_text: I, GEORGE THOMPSON DICKINSON of the City and County of Newcastle-upon-
Tyne Gentleman do hereby declare the nature of my invention for "IMPROVE-
MENTS IN MEANS FOR REVERSING THE MOTION OF STEAM ENGINES" and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:—
My Invention has for its object to provide means whereby the motion of Steam
Engines can be reversed without the necessity for the complicated gear hitherto
provided for the purpose.
According to my Invention I make the slide valves to slide upon a moveable
slide face which in its turn can be moved upon the facing of the steam chest.
The passages through the said chest communicating with the cylinder are made of
such a width that the ports through the moveable slide face are opposite the said
passages into whichever position the moveable slide face may be brought.
The slide valves themselves are provided with what may be regarded as double
sets of ports or steam ways one or the other set of which as the slides are
reciprocated is brought opposite the ports in the moveable slide face and valve
chest according to the position of the said slide face. These double ports or steam
ways in the slides are so arranged that when the moveable slide face is in one
position the ports or ways constituting the one set are in communication with the
cylinder through the passages on the said moveable face and the large passages in
the steam chest but when the moveable slide face is moved over into its other
position the entry for steam is reversed and the other ports or passages in the
slide which constitute the second set are in communication with the cylinder so
that steam is admitted in such manner as to reverse the engine. I prefer to make
the steam inlets and the exhausts on opposite sides of the cylinder or cylinders and
to provide the inlet and exhaust each with separate valves arranged as described.
Where two or more cylinders are employed side by side I prefer to make the
'moveable slide face by which the reversing action is obtained common to all the
cylinders and their valves so as to reverse them all at the same time.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
The drawing represents a longitudinal section of an engine cylinder provided
with means for reversing according to my Invention. The cylinder represented, is
one in which the steam inlet and exhaust ports are separate and on opposite sides
of the cylinder and are each provided with like reversing arrangements to be
operated simultaneously. The slide valves A and A' are respectively for closing
and opening the inlet and the exhaust ports. Each slide valve instead of sliding
directly upon the face of the ports in the steam chest of the cylinder slides upon
an intermediate moveable slide face B capable of being moved longitudinally upon
the said face of the ports in the steam chest independently of the slide valve.

page_text: b
The ports or passages C through the steam chest to the cylinder are made of such
a width that the ports 6 through the moveable slide face B are opposite the said
passages C into whichever position the said moveable slide face B may be brought.
The slide valves A. A' are provided with ports or passages a. a a³. When the
alide faces B are in the position sbewn the ports or passages C, b and a on the one
side of the piston, and the ports or passages C b and a on the other side of the
piston are alternately in communication as the slide valves A. A' are reciprocated
during the working of the engine. When however the slide face B is moved
longitudinally upon the face of the ports in the cylinder the ports or passages C b
and a on the one side of the piston and the ports or passages C. 6 and a on the
other side of the piston are alternately in communication as the slide valves A. A³
are reciprocated Therefore by moving the said slide faces B from one position to
the other the direction of working of the engine is reversed. In the drawing as
before stated I have shewn a cylinder with the exhaust and inlet ports distinct from
each other on opposite sides of the cylinder but I do not limit myself to this as it
will be evident that the arrangement can be used also in cases where the exhaust
and inlet ports are not arranged in this way. I have also shewn a cylinder with a
piston having a double piston rod as described in the Specification of my Patent
N° 1293 of 1884 but this it will also be understood is not essential to this present
Invention. The reversing slides B may be arranged outside the slide valves if
desired instead of between the slide valves and steam chest port face.
Where distinct passages for the inlet and exhaust are employed as shewn the
operating rods of the reversing slides will of course be connected or arranged to be
operated simultaneously.
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
For reversing the motion of Steam engines the employment of what has herein-
before been termed a moveable slide face capable of being moved independently
of the slide valve, substantially as hereinbefore described with reference to the
accompanying drawings.