mprovements in Steam Engines, which may be used in Gas, Water, Hot Air, or other Engines.
Year: 1891

page_text: Date of Application, 14th Nov., 1891
Complete Specification Left, 14th Sept., 1892-Accepted, 12th Nov., 1892
PROVISIONAL SPECIFICATION.
mprovements in Steam Engines, which may be used in Gas, Water,
Hot Air, or other Engines.
I, JOHN DODD, of Newton Mearns, near Glasgow, Renfrewshire, Scotland,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates more particularly to improvements in that type of engine
which are commonly known as pendulum or oscillating engines, and has for its
object to reduce friction between the working parts and to render the engine
reversable with dead cut off valves, to cut off steam at any part of the stroke, so
that the steam can be worked to the greatest degree of expansion possible.
In carrying out my invention, I fix the engine on a bed plate, cast in two or
more parts according to the size or power of the engine or if thought necessary
for strength, made out of wrought iron or steel plates to be rivetted together
with holes cut, from one compartment into the other. These holes must be as near
to the bottom of the compartment as possible, and if the bed plate is made in one or
two cast iron or several castings, the side holes must be cast in the bottom of every
compartment, to facilitate the draining off of the water from every compartment,
when the pump is at work feeding the boiler, which bed plate I call the heating
apparatus. Upon this bed plate will be secured the standard, which may be made
of cast or wrought iron and turned so as to be ornamental.
The said engine is supplied with steam from an ordinary boiler and fitted with a
pipe communicating with the heating apparatus. Each compartment of the latter
will be filled with cold water either from the water works main or pumped into it
by the engine, but every compartment when filled with water will be surrounded
by another compartment which will be filled with hot steam from the boiler, so
that whether made in cast iron or from boiler plates it must be made of sufficient
strength to stand the pressure of the boiler. It will be plainly seen that the cold
water thus surrounded by the hot steam on every side will, in a few minutes,
become as hot or nearly as hot when it enters or is pumped into the boiler to
generate steam, thus saving an enormous amount of fuel. The cylinder is mounted
on two pedestals at the top of the standard or column or on an entablement that
will be fitted to the said standard or column, and is oscillated by a crank. About
half way between the crank shaft is fitted a quadrant or link. This quadrant or
link will be hung by the centre in a straight line between the centre of the two
trunnions on which the cylinder oscillates or rocks. To this quadrant or link is
attached the valve spindle having a small round steel or iron roller or small steel
slide block, case hardened, the same as the quadrant or link. This roller or steel
block runs from one end of the quadrant or link to the other as the cylinder is
oscillating and is fitted to a lever that runs round to the front of the cylinder in a
straight line with the valve spindle. This lever is hung in or nearly in the centre,
so that on the quadrant or link being moved on its centre either up or down it
imparts motion to the slide valves. By this arrangement, if the quadrant or link
is placed at an equal distance from the centre of oscillation, the roller or steel
block will run from one end of the quadrant or link to the other without giving
any visible motion to the valve spindle or valves, so that if this quadrant or link is
attached to the governor balls if the engine runs away or is suddenly relieved of
its work, the balls will immediately rise and opperate on the lever attached to them
and will immediately send the quadrant or link up or down to its equal distance
and cover all the steam ports, thereby shutting off the steam from the cylinder and

page_text: stopping the engine entirely. By raising or falling this quadrant or link the engine
can be reversed and as the quadrant or link and its position determines the opening
of the steam ports, it is obvious that the governor balls will always keep the
quadrant or link in position to admit the proper quantity of steam and no more
than is sufficient to do the work. The dead cut off valves are fitted at either end
or both ends of the main slide valve by a separate spindle and are adjusted on this
spindle by a right and left handed screwed spindle so that they can be expanded
or contracted from one another by turning a small wheel attached to one end of
this spindle, by means of which the steam can be cut off at any part of the stroke.
At the other end of this spindle is fitted a small lever which is also attached to
the spindle of the main slide valve, at one end of this small lever is a dead centre
made fast to the cylinder or cylinder cover, the quadrant or link giving motion to
the main slide valve. This little radius lever gives a quicker motion to the top or
dead cut off valves, but the hole of this little radius lever must be formed with a
very small slot, so as to allow them to remain stationary for an instant of time,
while the main slide valve is returning over the steam ports.
The described engine I may form with or without steam chest or steam box
governors dead cut off valves or reversing lever, I also reserve the right to place
the quadrant or link in a stationary place to give the main slide valve its proper
travel. The dead cut off valves are screwed to their place to cut off at the proper
part of the stroke and so to admit the proper quantity of steam into the cylinder
to do the work; or to use the governor and dispense with the dead cut off valves,
the feed pipe is arranged to admit the steam through one of the trunnions from
where it passes down the side of the cylinder to half way where it turns round to
the bottom or main slide valve which is cast hollow and will get filled with steam.
The latter then runs along the said valve, to each of the dead cut off valves and
passes up through the main slide valve and into the dead cut off valves, which are
cast hollow and thus let the steam down through the main slide valve into the
cylinder. The surfaces of these valves are scraped up to a very fine surface to be
kept steam tight and the three slide valves themselves kept to the cylinder face by
two or more iron bars from the cylinder, fitted with spiral springs. The latter are
screwed down just as far as will keep them to their proper faces without letting
any steam escape. It will be understood that by this arrangement I do away with
the steam chest or box, thereby saving steam chest and lid and all the bolts and
nuts besides spindle glands and the trouble of the packing the same, but what is of
more importance I balance the valves, so that I take away the great amount of
friction on all slide valves and save all the wear and tare thereof.
I may fit each cylinder with motion or slide bars but in large slow going engines
they will not be required, but in small engines which have to run at a great speed,
there will be two slide bars, which may be cast on the cylinder cover or steel bars
screwed onto the cylinder end.
CAT
1
1001
F. BOSSHARDT & Co.,
Agents to Applicant.
COMPLETE SPECIFICATION.
Improvements in Steam Engines, which may be used in Gas, Water,
Hot Air, or other Engines.
I, JOHN DODD, of Newton Mearns, near Glasgow, Renfrewshire, Scotland,
Mechanical Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention relates more particularly to improvements in that type of engine
which are commonly known as pendulum or oscillating engines, and has for its
object to reduce friction between the working parts and to render the engine

page_text: reversable with dead cut off valves, to cut off steam at any part of the stroke, so
that the steam can be worked to the greatest degree of expansion possible.
have caused to
be appended hereunto one sheet of drawings marked with letters of reference indi-
cating like parts in the various figures.
And in order that my invention may be more fully understood
Figs. 1 & 2 are sectional side views and Fig. 3 a sectional end view of an engine
constructed in accordance with my invention.
Fig. 4 is a sectional side view of a modification of the valve chest.
In carrying out my invention and referring to Figs. 1, 2 & 3, I fix the engine on
a bed plate a, cast in two or more parts according to the size or power of the
engine or if thought necessary for strength, made out of wrought iron or steel
plates to be rivetted together with holes cut, from one compartment into the other.
These holes must be as near to the bottom of the compartment b, c, as possible, and
if the bed plate a is made in one or two cast iron or several castings, the side holes
must be cast in the bottom of every compartment b, c, to facilitate the draining off
of the water from the latter when the pump is at work feeding the boiler, which
bed plate a I call the heating apparatus. Upon the bed plate a is secured the
standard d, which may be made of cast or wrought iron and turned so as to be
ornamental.
The said engine is supplied with steam from an ordinary boiler and fitted with a
pipe e communicating with the bed plate or heating apparatus a. The compart-
ments c are filled with cold water either from the water works main or pumped
into it by the engine, the compartment c being surrounded by the compartment b
filled with hot steam from the boiler, so that whether made in cast iron or from
boiler plates it must be made of sufficient strength to stand the pressure of the
boiler. It will be plainly seen that the cold water thus surrounded by the hot
steam on every side will in a few minutes, become as hot or nearly as hot when
it enters or is pumped into the boiler to generate steam, thus saving an enormous
amount of fuel. The cylinder f is mounted on two pedestals g at the top of the
standard d or column or on an entablement that will be fitted to the standard or
column d, and is oscillated by a crank h. About half way between the crank
shaft is fitted a quadrant or link k. This quadrant or link kis hung in the
centre in a straight line between the centre of the two trunnions f¹ on which the
cylinder oscillates or rocks. To the quadrant or link k is attached, by means of
a lever 1, the valve spindle m having a small round steel or iron roller or small
steel slide block n case hardened, the same as the quadrant or link k. This roller
or steel block n runs from one end of the quadrant or link k to the other, see
Fig. 2, as the cylinder f is oscillating the lever passing to the front of the
cylinder in a straight line with the valve spindle m. The lever is hung in or
nearly in the centre, so that on the quadrant or link k being moved on its centre
either up or down it imparts motion to the slide valves o, p. By this arrangement,
if the quadrant or link k is placed at an equal distance from the centre of oscillation,
the roller or steel block n will run from one end of the quadrant or link k to the
other without giving any visible motion to the valve spindle m or valves o, p, so
that if the quadrant or link k is attached to the governor balls, if the engine runs
away or is suddenly relieved of its work, the balls will immediately rise and operate
on the lever attached to them and will immediately send the quadrant or link k
up or down to its equal distance and cause the valves o to cover all the steam
ports p' thereby shutting off the steam from the cylinder f and stopping the engine
entirely. By raising or falling this quadrant or link k, as shown in dotted lines
Fig. 2, the engine can be reversed and as the quadrant, or link and its position
determines the opening of the steam ports p' it is obvious that the governor balls
will always keep the quadrant or link k in position to admit the proper quantity of
steam and no more than is sufficient to do the work. The dead cut off valves p
are fitted at either end or both ends of the main slide valve o by a separate
spindle and are adjusted thereon by furnishing it with a right and left handed
screw, so that they can be expanded or contracted from one another by turning a

page_text: small wheel r attached to one end of the spindle by means of which the steam
can be cut off at any part of the stroke. At the other end of the spindle g is
fitted a small levers which is also attached to the spindle t of the main slide
valve o, at one end of this small levers is a dead centre u made fast to the
cylinder for cylinder cover 12, the quadrant or link k giving motion to the main
slide valve o. The little radius lever s gives a quicker motion to the top or dead
cut off valves p but it must be formed with a very small slot s' so as to allow them
to remain stationary for an instant of time, while the main slide valve o is returning
over the steam ports p.
The described engine I may form with or without steam chest or steam box,
governors, dead cut off valves, or reversing lever, I also reserve the right to place
the quadrant or link k in a stationary place to give the main slide valve o its proper
travel. The dead cut off valves p are screwed to their place to cut off at the proper
part of the stroke and so to admit the proper quantity of steam into the cylinder f
to do the work, or the dead cut off valves p may be dispensed with and a governor
employed in lieu thereof. The feed pipe e¹ is arranged to admit steam through one
of the trunnions f¹ from where it passes through a port f half way down the
cylinder f, and through a port p² in the main slide valve o, into the dead cut off
valves P which convey the steam through the ports p³ in the main slide valve o
through ports p' into the cylinder f. The surfaces of these valves o, p, are scraped
up to a very fine surface to be kept steam tight and the three slide valves o, p,
themselves kept to the cylinder face by two or more iron bars v from the
cylinder fitted with spiral springs w.
The latter are screwed down just as far as will keep them to their proper faces
without letting any steam escape. It will be understood that by this arrangement
I do away with the steam chest or box, thereby saving steam chest and lid and all
the bolts and nuts besides spindle glands and the trouble of the packing the same,
but what is of more importance I balance the valves, so that I take away the great
amount of friction on all slide valves and save all the wear and tear thereof.
I may fit each cylinder with motion or slide bars but in large slow going engines
they will not be required, but in small engines which have to run at a great speed,
there will be two slide bars, which may be cast on the cylinder cover or steel bars
screwed onto the cylinder end.
Referring to Fig. 4, in some cases I may dispense with the valves p and surround
the valves o with a steam chest x, a metal plate y being held tight against the top
of the valve o by means of springs y¹.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim, is-
"In steam engines with oscillating cylinders."
1st. The general construction and combination of parts constituting my invention
operating substantially as and for the purpose set forth.
2nd. The bed plate a formed with a number of compartments 6 & c the com-
partment c serving for the reception of cold water and the compartment 6 for steam,
whereby the cold water in the compartment c is heated, to be afterwards forced
into the boiler, substantially as and for the purpose set forth.
3rd. The employment of the quadrant or link k, substantially as and for the
purpose set forth.
4th. The arrangement of valves o & p and connections with the quadrant or
link k, substantially as and for the purpose set forth.
Dated this 13th day of September 1892.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.