Improvements in Steam Engines.
Year: 1894

page_text: Date of Application, 16th Nov., 1894
Complete Specification Left, 2nd Aug., 1895-Accepted, 7th Sept., 1895
Improvements in Steam Engines.
I, EDWARD HOPKINSON, D.Sc. Engineer, of The Salford Iron Works,
Manchester, do hereby declare the nature of this invention to be as follows:-
My invention relates to a construction of steam engine and especially of the
valves for admitting steam and discharging exhaust in such a manner that
the valves are balanced in respect of pressure and that the space in the passages is
reduced to a minimum. When the engine is single acting I arrange it so that the
connecting rod in both strokes is subject to tension, and may therefore be lighter
than that of an engine in which it is subject to thrust, that there is free escape of
water due to condensation or priming-and that there is no cooling action on the
entering steam such as results from the issue of exhaust through the entering
passage.
The engine may be vertical having its cylinder above the crank shaft. In this
case the steam acts only under the piston, being supplied and discharged by two
separate piston valves which slide parallel to the main piston in cylindrical casings
formed in the bottom cover of the cylinder, and are linked to opposite ends of a
sway beam worked by an eccentric on the shaft below. The one valve is thus
made to ascend as the other descends so that the pressure is balanced, and each by
its ascent and descent covers and uncovers lateral ports by which the steam is
For a double
admitted over the one piston, and is discharged over the other.
acting engine there is at each end of the cylinder a pair of valves such as are
described above. Several cylinders may be arranged with their pistons connected
to a crank or cranks on one shaft so as to work either as combined or compound
engines.
The cylinder or cylinders, instead of being vertical, may be horizontal or
inclined, and the slippers, connecting rods, and cranks may all be enclosed in a
steam tight casing, having stuffing boxes through which the shaft passes.
Deted this 16th dev of November 1894.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Steam Engines.
I, EDWARD HOPKINSON D.Sc., Engineer, of The Salford Iron Works,
Manchester 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 to a construction of steam engine and especially of the
manner that
valves for admitting steam and discharging exhaust in such a
the valves are balanced in respect of pressure and that the space in the passages is
reduced to a minimum. Figs. 1 and 2 are longitudinal and transverse sections of a
single acting compound engine according to my invention. The engine being

page_text: single acting as shewn, I arrange it so that the connecting rods A A¹ in both
strokes are subject to tension, and may therefore be lighter than those of engines
in which they are subject to thrust. I also arrange the valves so that there is free
escape of water due to condensation or priming and that there is no cooling action
on the entering steam such as results from the issue of exhaust through the
entering passage.
The engine may be vertical as shewn having its cylinders above the crank shaft.
In this case the steam acts only under the piston in each cylinder being supplied
and discharged in each case by two separate piston valves B. C. which slide
parallel to the main piston in cylindrical casings formed in the bottom cover of the
cylinder, and are linked to opposite ends of a sway beam D worked by an
eccentric E E¹ on the shaft below. The one valve is thus made to ascend as the
other descends so that the pressure is balanced, and each by its ascent and descent
covers and uncovers lateral ports by which the steam is admitted over the one
piston, and is discharged over the other. If the engine were double acting there
would be at each end of the cylinder a pair of valves such as B, C described above.
The engine might be a simple one with only one cylinder, or several cylinders
might be arranged with their pistons connected to a crank or cranks on one shaft
so as to work either as combined or a compound engine as shewn.
The cylinder or cylinders, instead of being vertical, may be horizontal or inclined,
and the slippers, connecting rods and cranks may be all enclosed, as shewn, in a
steam tight casing F, having stuffing boxes through which the shaft passes. The
weight of a heavy piston and its connections may be partly counterpoised by steam
pressure acting under the piston of a cylinder G.
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. Valves for supply and discharge of a steam cylinder consisting of two pistons
connected to opposite ends of a sway beam worked by an eccentric, each piston
working in a cylindrical cavity formed in the end of the cylinder and covering and
uncovering lateral ports, substantially as and for the purpose set forth.
2. A single acting engine constructed and operating substantially as described
with reference to the accompanying drawings.
Dated this 2nd day of August. 1895.
ABEL & IMRAY,
Agents for the Applicant.