Year: 1889

page_text: _ute of Application, 27th Feb., 1889
Complete Specification Left, 23rd Mar., 1889
Complete Specification Accepted, 8th June, 1889
I FREDERICK JOHN BURRELL of Thetford in the county of Norfolk Engineer do
hereby declare the nature of this invention to be as follows:-
The object of this Invention is to provide a simple and cheap form of compound
engine, specially applicable to the class generally known as Portable and Traction
Engines where the Engine is placed upon the top of the boiler; whereby one crank,
one connecting rod and one link motion only is necessary both for the high and
low pressure cylinders, and so arranged that an ordinary high pressure single
cylinder engine by simply removing the cylinder and substituting my compound
cylinders, may be converted into a compound engine, without baving to raise the
centre line of the engine crank shaft or make any other extensive alterations. I place
one cylinder above the other with their centres above and below the centre line of
the crosshead pin, but in order to obtain more room for the lower cylinder I may.
arrange the centres of the cylinders diagonally and not perpendicularly over each
other.
I connect the two piston rods to one crosshead of which the slide-blocks are
made longer than usual and have side flanges, so as to resist any rocking tendency
caused by unequal pressures upon the large and small pistons. I preferably use two
slide valves, one placed above the other and working in separate steam chests, and
operated by spindles connected to a crosshead, so that one link motion suffices to
drive both valves. The exhaust steam after it leaves the small cylinder passes directly
into the low pressure steam chest. Both cylinders with their steam chests, stop,
safety and throttle valves are arranged compactly together so that they take up..
little, if any more room than an ordinary high pressure single cylinder as usually
fitted.
Dated this 26th day of February 1889.

page_text: COMPLETE SPECIFICATION.
Improvements in Compound Portable and Traction Engines.
I FREDERICK JOHN BURRELL of St. Nicholas Works Thetford in the county of
Norfolk 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:-
The object of this Invention is to provide a simple and cheap form of Compound
Engine specially applicable to the class generally known as Portable and Traction
engines where the Engine is placed upon the top of the Boiler, whereby one crank,
one connecting rod and one link motion only is necessary for both high and low-
pressure cylinders, and so arranged that an ordinary high pressure single-cylinder
engine by simply removing the cylinder and substituting my improved cylinders
may be converted into a Compound engine without having to raise the centre line
of the engine crank shaft or make any other extensive alterations. I place one
cylinder above the other with their centres above and below the centre line of the
crosshead pin, but in order to obtain more room I may arrange the centres of the
cylinders diagonally and not perpendicularly over each other. I connect the piston
rods to one crosshead of which the slide blocks are made longer than usual and have
side flanges, so as to resist any rocking tendency caused by unequal pressures upon
the large and small piston rods. I preferably use two slide valves, one placed above
the other and working in separate steam chests, and operated by spindles connected
to a crosshead, so that one link motion suffices to drive both valves. The exhaust
steam after it leaves the small cylinder passes directly into the low pressure steam
chest. Both cylinders with their steam chests, stop, safety and throttle valves are
arranged compactly together so that they take up little if any more room than an
ordinary high pressure cylinder as usually fitted.
Fig. 1 shews the ordinary high pressure single cylinder as usually fitted to
"Portable" and "Traction" Engines.
Fig. 2 is an end view of my Improved Compound cylinders.
Fig. 3 is an elevation and Fig. 4 a plan of the same. In Fig. 1, a is the centre of
the cylinder b is the slide valve spindle, c is the throttle valve spindle, d the starting
valve rod, e the exhaust pipe and the boiler.
In Figs. 2, 3, 4, A is the centre of the crosshead pin which is midway between
the centre of the high pressure cylinder H and that of the low pressure cylinder L.
The high and low pressure cylinders are fitted with pistons and piston rods in the
usual manner, O being the high pressure piston rod, and P the low pressure piston
rod, both piston-rods are connected to one crosshead Q which is provided with suitable
lugs for the purpose. The slide blocks R of the crosshead Q are made much longer
than usual and have side flanges S so as to resist any rocking tendency caused by
unequal pressures upon the large and small piston rods. B is the centre of the valve
motion which is midway between the high pressure slide valve spindle M and the low-
pressure slide valve spindle N, both spindles are connected together and to the rod T

page_text: by the yoke or crosshead Y. The rod T is connected to the link motion in the usual
manner. C is the throttle valve spindle which is operated by the Governors, D is the
starting valve rod; W, W, are the safety valves. By placing the centres of the high
and low pressure cylinders H and L upon a diagonal line passing through the centre
of the crosshead pin A, I am enabled to make my compound cylinders so compact
that they can easily replace an ordinary single cylinder of equal power, as shewn in
Fig. 1.
The main centres (that is in Figs. 1 and 2 the centres a and A, 6 and B) having the
same positions relative to the boiler f, F, and especially the distances x and X, which
is the distance from the top of the boiler to the centre of the engine crank shaft being
the same in both cases.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is
1. In compound Portable and Traction engines and where the engine is placed
upon the top of the boiler; placing one cylinder diagonally above the other and
connecting the two piston rods to one crosshead.
2. In engines fitted upon the top of the boiler, the arrangement and combination of
parts substantially as described and illustrated by the accompanying drawings for the
purpose set forth.
Dated this 22nd day of March 1889.