IMPROVEMENTS IN STEAM AND OTHER ENGINES to be as follows:
Year: 1884

page_text: I WILLIAM LOWRIE of Appold Street Finsbury in the County of Middlesex
Engineer do hereby declare the nature of my invention for "IMPROVEMENTS IN
STEAM AND OTHER ENGINES to be as follows:-
"
According to this invention I construct engines to be worked by steam or other
elastic fluid under pressure in such a manner that the admission of steam to the
cylinder at the commencement of each stroke is controlled by the angular motion
of the connecting rod (used for converting the reciprocatory motion of the piston
into the rotary of the crank shaft) whilst the cut off of the supply of steam to the
cylinder at any desired part of the stroke is controlled by another valve which is
moved by the movement of the piston.
I effect this as follows:-
Each cylinder I make single acting its piston I make with a cylindrical extension
from its rear end to pass through an opening in the back end cover of the cylinder
and to fit within a fixed cylindrical casing which extends from the back end of the
cylinder. This chamber I surround with a steam space and form ports in the sides
of the chamber. The sides of the chamber form a fixed valve face and the
cylindrical extension from the piston serves as a slide valve to control the passage
of steam through the ports of this valve face.
In it I form two sets of ports-through one set steam can pass into its interior
whenever this set of ports comes opposite to the ports in the fixed valve face and
through the other set steam can pass from the interior of the slide valve to the
cylinder.
Working within this slide valve is an inner slide valve by which a communication
can be established between the two sets of ports of the outer slide valve.
The inner valve I make to pass right through the outer slide valve and a roller
carried by its forward end I make to rest against a cam surface formed upon the
end of the connecting rod in rear of the pin which connects this rod to the piston.
Steam is always admitted from the steam chamber to the rear end of the slide
valves so that the forward end of the inner slide valve is always held up to and
against the cam surface. The piston is also in this way kept constantly pressed
towards the crank shaft so that the connecting rod is kept always in compression
which is advantageous in quick running engines.

page_text: To exhaust steam from the cylinder at the end of its forward stroke I make the
piston at the end of the stroke to pass beyond the end of the exhaust ports formed
through the sides of the cylinder into an exhaust chamber. Through these the
greater part of the steam in the cylinder will be exhausted. The angular motion
of the connecting rod at the end of the stroke can also be made to move the inner
slide valve (if an inner slide valve be used) so as to put the ports in the outer slide
valve which are open to the interior of the cylinder into communication with ports
at the ends of passages which are formed through the bottom of the piston and
which lead to other ports or openings formed at the sides of the piston opposite to
the exhaust ports in the sides of the cylinder so as to give a connection with the
exhaust during the whole of the return stroke.
The action of the valves is as follows: At the completion of the back stroke of
the piston the inner slide valve will be moved endwise by the angular motion of
the connecting rod so as to bring it into position to allow steam to pass from the
steam chamber to the cylinder. After the completion say of about one third of the
stroke the outer slide will by the movement of the piston be moved into a position
to cut off all passage of steam from the steam chamber to the cylinder and this cut
off will be effected very rapidly. At the completion of the stroke the exaust will
take place as above described.
Any desired number of cylinders may be set at equal angles around the crank
shaft and the connecting rods from their pistons all be made to work upon one
crank pin. Or a number of cylinders may be ranged in a line and made to work
on to separate cranks at equal angles to one another.

page_text: COMPLETE SPECIFICATION.
I WILLIAM LOWRIE of Appold Street Finsbury in the County of Middlesex
Engineer do hereby declare the nature of my invention for "IMPROVEMENTS IN
STEAM AND OTHER ENGINES" and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement:-
According to this Invention I construct engines to be worked by steam or other
elastic fluid under pressure in such a manner that the admission of steam to the
cylinder at the commencement of each stroke is controlled by the angular motion
of the connecting rod (used for converting the reciprocating motion of the piston
into the rotary of the crank shaft) whilst the cut off of the supply of steam to the
cylinder at any desired part of the stroke is controlled by another valve which is
moved by the movement of the piston. I effect this as follows:-
Each cylinder I make single acting-its piston I make with a cylindrical
extension from its rear end to pass through an opening in the back end cover of the
cylinder and to fit within a fixed cylindrical casing which extends from the back
end of the cylinder. This chamber I surround with a steam space and form ports
in the sides of the chamber. The sides of the chamber form a fixed valve face and
the cylindrical extension from the piston serves as a slide valve to control the
passage of steam through the ports of this valve face.
In it I form two sets of ports-through one set steam can pass into its interior
whenever this set of ports comes opposite to the ports in the fixed valve face and
through the other set steam can pass from the interior of the slide valve to the
cylinder.
Working within this slide valve is an inner slide valve by which a communi-
cation can be established between the two sets of ports of the outer slide valve.
This inner valve I make to pass right through the outer slide valve and a roller
carried by its forward end I make to rest against a cam surface formed upon the
end of the connecting rod in rear of the pin which connects this rod to the piston.
Steam is always adinitted from the steam chamber to the rear end of the slide
valves so that the forward end of the inner slide valve is always held up to and
against the cam surface. The piston is also in this way kept constantly pressed'
towards the crank shaft so that the connecting rod is kept always in compression
which is advantageous in quick running engines.
To exhaust steam from the cylinder at the end of its forward stroke I make
the piston at the end of the stroke to pass beyond the end of exhaust ports formed
through the sides of the cylinder into an exhaust chamber. Through these the
greater part of the steam in the cylinder will be exhausted. The angular motion
of the connecting rod at the end of the stroke can also be made to move the inner
slide valve so as to put the ports in the outer slide valve which are open to the
interior of the cylinder into communication with ports at the ends of passages
which are formed through the piston and which lead to other ports or openings
formed at the sides of the piston opposite to the exhaust ports in the sides of the
cylinder so as to give a connection with the exhaust during the whole of the
return stroke or nearly so,

page_text: The action of the valves is as follows:-At the completion of the back stroke of
the piston the inner slide valve will be moved end wise by the angular motion of
the connecting rod so as to bring it into position to allow steam to pass from the
steam chamber to the cylinder. After the completion say of about one third of
the stroke the outer slide will by the movement of the piston be moved into a
position to cut off all passage of steam from the steam chamber to the cylinder and
this cut off will be effected very rapidly. At the completion of the stroke the
exhaust will take place as above described.
Any desired number of cylinders may be set at equal angles around the crank
shaft and the connecting rods from their pistons all be made to work upon one
crank pin. Or a number of cylinders may be ranged in a line and made to work
on to separate cranks at equal angles to one another.
Figure 1 of the drawings hereunto annexed shows a longitudinal vertical section.
Figure 2 a plan view and Figure 3 a transverse vertical section of a single cylinder
engine constructed as above described. Figures 4 and 5 are similar vertical sections
shewing modified forms of the hollow cylindrical extension from the piston and of
the inner slide valve working therein and also a modified way in which the angular
motion of the connecting rod may be made to give endway motion to the inner
slide valve. Figures 6 and 7 are similar vertical sections of other modifications in
the forms of these parts.
In Figures 1, 2 and 3, A is the cylinder of the engine. B the piston working
therein, C is the crank shaft and D the connecting rod. E is the hollow cylindrical
extension from the piston and which fits at its sides within a cylindrical casing F
which extends from the back end of the cylinder. G is the inner slide valve fitting
within the hollow extension E. G¹ is a roller at its lower end which is kept
bearing constantly against a cam projection DI on the connecting rod. H is a
steam chamber surrounding the cylindrical casing F which extends from the back
of the cylinder. Steam is admitted to this chamber through an inlet H¹ (see
Figure 3). In the sides of the casing F are ports or openings F' and in the sides
of the hollow extension E are two sets of ports E¹ E; around the inner
valve G is also a recess G* which can overlap both sets of these latter ports.
This recess can also be brought to overlap the lower set of ports E' and the inner
ends of ports B₁ formed through the body of the piston B. A¹ are ports in the
sides of the cylinder opposite to which the outer ends of these ports B' are brought
during the greater part of the stroke of the piston. The upper edge of the piston
also comes below the upper edge of the ports A¹ when the piston is at the bottom
end of its stroke.
The ports A through the side of the cylinder open into an exhaust chamber I
which surrounds the cylinder and may also surround the steam chamber Has
shewn. I is an outlet from the exhaust chamber I.
The exhaust chamber I and cylinder A are as shewn carried on the top of a
casing within which the crank of the crank shaft is enclosed. F¹ are openings by
which steam is continuously admitted to the upper part of the cylindrical casing F
so as to bear constantly upon the upper end of the tubular piston rod and the
piston valve which works therein. J is a spiral spring which also bears down con-
stantly on the top of the piston valve and keeps it pressing downwards against the
cam D' at times when the engine is running and steam turned off from the steam
chainber.
The action of the engine is as follows:-
The crank shaft of the engine revolves from right to left in the direction of the
arrow (Figure 3). The piston is shewn at the top of the stroke and the ports E' in
its hollow extension E are open to the ports F' so that steam can enter them from
the steam chamber.
As the piston commences its down stroke the inner slide valve will be moved
upwards within the hollow extension E and the recess G* which is overlapping the
ports E' will commence to overlap also the ports E¹ steam will therefore be adinitted to

page_text: the top of the cylinder through the ports E¹ cavity G* and ports E. When the piston
has completed about a third of its downward stroke the ports E' in the hollow exten-
sion E will by the downward movement of the piston have been brought below the
ports F and the further admission of steam to the cylinder will be so cut off. Just
before the completion of the downward stroke of the piston the upper edge of the
piston will have passed below the upper edge of the ports A¹ in the sides of the
cylinder A and will so open the upper part of the cylinder to the exhaust: At
the completion of the downward stroke the inner slide valve will again have been
brought into the same position relatively to the hollow extension E as it occupied
when the piston was at the top of its stroke and as it is shewn in the drawing but
it will then be moving downwards. Shortly after the commencement of the up
stroke the recess in the inner slide valve which now overlaps the ports E* will
commence also to overlap the inner ends of the ports B₁ the outer ends of these
ports being at the same time opposite to the ports A' in the sides of the cylinder
thereby putting the upper end of the cylinder in communication with the exhaust
through the ports E' B₁ and A' just before the upper edge of the piston rises above
the ports A' and thereby closes this direct outlet to the exhaust and the upper end
of the cylinder A remains open to the exhaust almost to the end of the upward
stroke through the ports E' B₁ and A'. It is not necessary that the tubular
casing F should be prolonged up to the top of the steam chamber H as shown at
Figures 1 and 3-it is sufficient for it to project upwards a distance into the steam
chamber as shown at Figures 4 and 5 so that steam may enter the ports El when
they rise above its top and be cut off from them when they descend below it. In
these figures also I have shown the lower end of the inner slide valve connected by
a link with an arın D₁ extending from the connecting rod so that the inner slide
valve is moved endwise to and fro by the rocking of this arm just as in the
construction shown at Figures 1, 2 and 3 it is moved to and fro by the rocking
of the cam D¹.
In the modification shown at Figures 6 and 7 the lower end of the inner slide
valve has an arm descending from it and carrying a pin which passes through a
square block K. This block lies in a slot in an arm D¹ extending from the con-
necting rod so that the inner slide valve is moved endwise to and fro by the
rocking of the connecting rod just as in the constructions previously described.
In these figures also I have shown a means of supplying oil to the pin of the con-
necting rod through a telescopic tube one half of which passes through the inner
slide valve and the other half of which is at its upper end held fixed and is open
so that oil may be passed down through it. In most cases however it is unnecessary
to use an oiling arrangement of this kind.
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
1. In steam and other engines in which single acting cylinders are used the com-
bination of a hollow cylindrical extension from the piston acting as a slide valve to
control the cut off of steam from the cylinder after a portion of the stroke bas been
completed and of an inner slide valve moved endwise to and fro in such cylindrical
extension by the angular motion of the connecting rod to govern the first admission
of steam to the cylinder substantially as described.
2. In steam and other engines in which single acting cylinders are used the
employment of a hollow cylindrical extension from the piston and an inner slide
valve acting in the above manner in combination with exhaust ports in the sides of
the cylinder beyond which the piston travels at the extreme end of its forward
stroke substantially as described.
3. In steam and other engines in which single acting cylinders are used the
employment of a hollow cylindrical extension from the piston and an inner slide
valve acting in the above manner and of exhaust ports in the sides of the cylinder
beyond which the piston travels at the extreme end of its forward stroke

page_text: in combination with a further exhaust through the piston and through these
exhaust ports controlled by the movement of the inner slide valve substantially as
described.
4. The construction of steam and other engines substantially as herein before
described and illustrated in the drawings annexed.