Improvements in Engines Worked by Fluid Pressure.
Year: 1892

page_text: Date of Application, 11th Oct., 1892
Complete Specification Left, 11th July, 1893—Accepted, 11th Dec., 1893
PROVISIONAL SPECIFIcation.
Improvements in Engines Worked by Fluid Pressure.
1, CHARLES FERDINAND DE KIERZKOWSKI-STEUART, of 4, Copthall Buildings,
E.C. Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
As steam and other engines worked by elastic fluids are usually arranged, when
the load on the engine varies, the amount of working fluid which acts in the
cylinder is varied either by altering the area of the supply passage or by varying
the degree of expansion.
With one particular load, the conditions may be such as to give great efficiency,
but when the conditions have to be changed in order to suit a different load, the
efficiency may become considerably reduced. One serious loss of efficiency is due to
the work performed in expelling exhaust (a work which is useless in developing
power) and this loss is the greater the greater the volume that has to be expelled
against the atmospheric or other pressure external to the cylinder..
Again, in hydraulic engines, when the load is less than the maximum part, often
a very large part of the water under pressure is entirely wasted.
My invention relates to means of reducing losses of efficiency when the load on
the engine is varied, by so constructing the engine that the stroke of the piston
and consequently tho volume occupied by the fluid that has to do work in the
cylinder and to be expelled from the cylinder after performing work therein, can be
varied to suit variations of load whilst the pressure or mean pressure in the cylinder
may be kept uniform. For this purpose, link the crank pin to the end of a lover'
which, as the crank revolves, oscillates in front of the cylinder which is open
ended. A slipper which is linked by a connecting rod to the piston is fitted to
slide along this lever so that it can be moved nearer to or farther from its fulcrum
according as the stroke of the piston has to be lessened or increased. In order
that, however the stroke may be varied, there shall always be the same clearance
behind the piston at the extreme of its instroke. I make the path on the lever
along which the slipper is fitted to slide an arc of a circle attuck from the point
where the connecting rod is jointed to the piston when the piston is at the
extremity of its instroke and the crank at its corresponding dead centre. Tho
slipper can be moved along the lever either by hand or by means of a suitable
governor working a spindle which passes centrally through the pivot of the
Oscillating lever and operates a screw or other gear whereby the slipper is moved!
The valves for admission and emission of the working fluid may be of any known
kind, the admission valve for elastic fluid being preferably worked by a cam having
a dwell, determining the period of cut off, that can be varied either conformably to
the variation of the piston stroke or otherwise as desired.
In some cases I prefer to arrange the cam in combination with automatic
mechanism making the adjustment of the cut off dependent on the pressure at which
the exhaust is expelled.
Two or more cylinders may be arranged as described in connection with one
crank, and they may be worked either as simple or as compound or multiple.
expansion engines. With suitable modifications of the valve gear and other parts,
gas or oil motor engines as well as hydraulic engines may be arranged to operate
as described.
Dated this 11th day of October 1909
ABEL & IMRAY,
Agents for the Applicant,

page_text: COMPLETE SPECIFICATION.
Improvements in Engines Worked by Fluid Pressure.
•
I, CHARLES FERDINAND DE KIERZKOWSKI-STEUART of 4 Copthall Buildings
E.C. Civil 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:-
As steam and other engines worked by elastic fluids are usually arranged, when
the load on the engino varies, the amount of working fluid which acts in the
cylinder is varied either by altering the area of the supply passage or by varying
the degree of expansion.
With one particular load, the conditions may be such as to give great efficiency,
but when the conditions have to be changed in order to suit a different load, the
efficiency may become considerably reduced. One serious loss of efficiency is due
to the work performed in expelling exhaust (a work which is useless in developing
power) and this loss is the greater the greator the volume that has to be expelled
against the atmospheric or other pressure external to the cylinder.
Again in hydraulic engines, when the load is less than the maximum, part, often
a very large part, of the water under pressure is entirely wasted.
My invention relates to means of reducing losses of efficiency when the load on
the engine is varied, by so constructing the engine that the stroke of the piston,
and consequently the volume occupied by the fluid, that has to do work in the
cylinder and to be expelled from the cylinder, after performing work therein, can
be varied to suit variations of load, whilst the pressure or mean pressure in the
cylinder may be kept uniform.
These results are attained by arrangements such that the volume of working
fluid admitted per stroke can be varied proportionally to the work that has to be
done at different powers, whilst the initial pressure and ratio of expansion and
hence the mean pressure can be maintained practically constant.
This is accomplished by connecting the piston of a single acting cylinder to the
crank through the medium of a rocking lever or arm on which the piston rod acts
in a manner similar to that of the foot on the treadle of a lathe. Provision is
made for altering the leverage at which the piston acts on the rocking arm, so that,
while the crank throw remains constant, the piston has greater or less travel. The
point of connection of the piston connecting rod to the rocking arm is arranged to
move in a curve such that, whatever be the stroke of the piston, it always returns
to the same point in the cylinder at the end of each instroke. The clearance
behind the piston is thus maintained uniform, the variation in the piston. stroke
taking place in the direction of the outward stroke. The valve gear may be
arranged to cut off at a point of the stroke which varies according to the ratio
which the piston displacement at different powers bears to the constant cylinder
clearance, and thus a uniform ratio of expansion can be maintained under all
variations of piston stroke. Release, compression and admission can then be
commenced at the same fraction of the stroke at all powers.
Figs.. 1 and 2 of the accompanying drawings are elevations partly in section, on
planes at right angles to each other of the working parts of an engine according to
my invention, Fig. 3 being a sectional plan on the centre line Z in Fig. 2.
The piston G, which is made with an outer shell of depth equal to the whole
length of the cylinder so as to avoid formation of shoulders when the stroke is
varied, has a pio E linked by a connecting rod F, terminating in a forked end H
to a pin I passing through eyes of a slipper J, which is fitted to slide along dove-
tail guides formed on a rocking lever or arm A. This rocking arm has its one end
pivotted at O to the fixed framing of the engine, its other end is linked by a
connecting rod C to the crank D of the engine shaft B. On the pivot O, is fitted
free to turn a bracket in a bearing in which is journalled the boss L of a worm

page_text: wheel M. In this worm wheel and its boss there is an internal screw thread so
that they together form a nut for a screwed rod K which terminates in an eye
embracing the pin 1. Gearing with the worm wheel M is a worm N which is fixed
on a spindle o passing through the pivot O which is tubular. When the spindle o
is turned, turning the worm N, the worm wheel M is also turned, and this, acting
as a nut on the screwed rod K, causes the slipper J to move along the guides of the
rocking arm A nearer to or farther from the fulcrum according to the direction in
which o is turned. The stroke of the piston G is thus varied while the throw of
the crank D remains constant. In order that the piston G may terminate its
instroke at the same place in the cylinder, however its outstroke may be varied, the
guides on A along which J. moves are shaped as a circular arc struck from the
centre of the pin E when the piston is at the extreme of its instroke.
The variation of the piston stroke may be effected by turning the spindle o by
hand or by suitable gearing actuated by the engine or by a subsidiary engine
which may be put in action by hand or by a suitable governor.
In Figs. 2 and 3 I have shewn mechanism by which the spindle o of one of a
pair of engines may be turned simultaneously with the like spindle of belonging to
a second parallel engine. For this purpose the spindlo o has in each case a
Tshaped end P, which, as shewn in Fig. 4 (which is a front view) engages in a
cross slot in the boss of a bevil. wheel R or of a sleeve R¹ in one piece with the
bevil wheel R which gears with another bevil wheel S turned by hand or by
mechanism connecting it to a governor. The slots Q in which the T heads P
engage are cut to allow sufficient play for the T heads resulting from the rocking
of the arm A without causing the worm wheel M to turn.
Figs. 5 and 6 shew a modified construction of the connections from the piston
pin E to the shaft B; the parts in these figures corresponding with the parts in
Figs. 1 and 2 being marked by similar letters. In this case, instead of jointing the
connecting rod F to a slipper, it is jointed to a pair of rollers J' which can roll
along the curved faces of the double rocking arın A; and, instead of linking these
arms by a connecting rod to the crank, they carry between them a roller C which
rolls on an eccentric D' fixed on the shaft B. As the engine is single acting, the
strain of Jon A and of C¹ on D¹ is always in the form of
pressure.
In engines arranged as above described, the valves for the admission and
emission of the working fluid may be of any known kind. When the fluid is clastic,
the admission valve is preferably worked by a cam having a dwell that can be varied
so as to determine the period of cut off, and, if desired, the dwell of the cam may
be varied conformably to the variation of the piston stroke.
Two or more cylinders for operating as described may be arranged radially
around a shaft to work a single crank or eccentric, or they may be arranged side
by side or tandemwise. When the engine works a water pump, an air compressing
pump, or its own air pump these may have their piston strokes varied as described
by connecting them, to the pistons of the engines..
Having now particularly described and ascertained the nature of my said invon-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
An engine worked by fluid pressure of which, while the throw of the crank or its
equivalent remains constant, the power can be varied by varying the piston stroke in
such a manner that the instroke of the piston always terminates in the same place,
substantially as and for the purposes set forth.
1
T •
ABEL & IMRAY,
Agents for the Applicant.