Improvements in Compound Engines.
Year: 1889

page_text: Date of Application, 31st Dec., 1889-Accepted, 1st Feb., 1890
Improvements in Compound Engines.
I, JAMES ANTHONY CLARKE of Port Moody in the Province of British Columbia
and Dominion of Canada, Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The Invention relates to compound tandem engines specially designed for marine
vessels to drive twin propellers.
My Invention will be described with reference to the accompanying drawings
forming part of this specification in which figure 1 is a plan view, and figure 2 a
side elevation, of the engine. Figure 3 is a sectional end elevation of the engine,
on line figure 1, looking in the direction of the arrow x¹, and figure 4 is a
reduced sectional end elevation of the same on line y-y figure 1, looking in the
direction of the arrow y¹. Similar letters of reference indicate corresponding parts
in all the figures.
B is the vertical high pressure cylinder, C its steam chest, D the steam inlet pipe,
and E the exhaust pipe. G is the low pressure cylinder placed in a vertical position
beneath the cylinder B, H the steam chest of cylinder G into which steam is
discharged from cylinder B. F is the piston rod to which the pistons of both
cylinders are attached. J is a cross-head on the piston rod F which is connected, by
the connecting rods K and K', with cranks L and L' of crank shafts N and N¹
mounted to turn in bearings on the bed O which also supports a frame O' carrying
the low-pressure cylinder G. On top of the latter there is a frame 02 supporting the
high-pressure cylinder B.
The valves in the steam chests H and C are connected with each other by the
valve rod P connected at its lower end, in the usual manner, with a reversing link Q
operated from eccentrics R and R' on one of the crank shafts N or N'. The arrange-
ment is such that the crank shafts N and N¹ are turned in opposite directions. The
position of the link Q can be changed, as is usual, by the reversing lever S so that
the motion of the crank shafts N and N₁ can be simultaneously reversed.
T and T¹ are cranks on the shafts N and N connected by rods U and U¹ with a
slide V mounted in vertical guide ways W supported on a frame 03 erected on the
base O. This arrangement serves as a governor, as will be hereinafter more fully
described.
The operation of the engine is as follows;-Live steam passes into the steam chest C,
through inlet pipe D, and operates the piston in the high-pressure cylinder B while
the exhaust from the latter acts on the piston in the low pressure cylinder G. The
piston rod F thus receives an up and down motion by the action of the steam in the
cylinders B and G, and as it is connected, by its cross-head J rods K and K' and the
cranks Land L', with the shafts N and N₁ the latter are rotated in opposite directions.
The rotation of the crank shafts N and N¹ works the slide V up and down in the
guide ways W.
The improved engine, as above mentioned, is especially designed for marine purposes
to drive twin screws secured directly on the crank shafts N and N' in front of the
cranks T and T. In case one of the screw-propellers should become disabled, the
power imparted to its shaft will be directly transmitted to the other shaft by means
of the cranks T T', the connecting rods U U¹, and the side V. For example if the
propeller on the shaft N' is disabled, the power imparted to said shaft N₁ is trans-
mitted, by the crank arm T' and the connecting rod U', to the slide V, which latter, by
the rod U and the cranks T, transmits its power to the crank shaft N so that by
this means the other screw propeller is caused to do all the work. In a heavy
rolling sea one of the propellers frequently gets partially out of the water while

page_text: the other is deeply submerged and when this happens the slide V will prevent
the flying around of the one propeller and will assist the other.
It will be understood that as the cross head J is secured directly on the
piston F and the rods K and K¹ are directly connected to the said cross-head, no
guide ways are used thus economizing power which would otherwise be lost in
friction and affording other attendant advantages.
A triple expansion can be used by arranging a third cylinder on top or under-
neath the other cylinders or by placing it forward of the cylinders and having two
more cranks (or the quadruple would be more effectually placed in a similar position)
in which case the sets of cranks might be at right angles to each other so that
there would be no dead centre.
This improved engine is easily kept in line, there are few working parts all of
which are readily accessible, and there is comparatively speaking little friction.
The governor can be attached to any twin propellers without altering the existing
engine from which they derive their power.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what
I claim is;
1. In an engine, a high pressure cylinder and a low pressure cylinder deriving
its motive fluid from the exhaust of the high pressure cylinder in combination
with a piston rod carrying the pistons of the two cylinders, a cross head secured
to said piston rod, connecting rods pivotally connected at opposite sides with said
cross-head, crank arms placed at angles to each other and connected with said
connecting rods, crank shafts carrying said crank arms and placed parallel with
each other, a reversing link operated from one of the said crank-shafts and operating
the valves in said high pressure and low-pressure cylinders, vertical guide ways
parallel with said cylinders, a slide therein, and connecting rods pivoted thereto
at their upper ends and connected at their lower ends to cranks on said shafts,
substantially as shewn and described.
2. In an engine, the combination, with two crank shafts and means for
rotating them, of crank arms secured on said shafts and standing at angles to each
other, connecting rods pivotally connected with said crank arms, a slide pivotally
connected with said connecting rods and guide ways in which said slide operates,
substantially as shewn and described.
3. In an engine, the combination, with guide ways W of a slide V mounted to
slide in said guide ways, connecting rods pivotally connected with said slide, crank
arms pivotally connected with said connecting rods and standing at angles to each
other, main crank shafts carrying said crank arms, and a compound engine operating
said crank shafts, substantially as shewn and described.
Dated 31st December 1889.
JAMES ANTHONY CLARKE.