IMPROVEMENTS IN STEAM ENGINES
Year: 1884

page_text: I JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of said Invention for "IMPROVEMENTS IN
STEAM ENGINES" which Invention has been communicated to me from abroad by
Messieurs Lecouteux and Garnier of Paris in the Republic of France Mechanical
Engineers to be as follows:-
This Invention has for its object providing an Engine suitable for transmitting
motion directly to machines requiring to be driven at a high rate of speed such as
Dynamo or Magneto Electric machines.fans circular saws and the like which aro
usually driven by means of multiplying gear or counter shafts interposed between
the machinery and the motor in order to obtain the requisite rapidity of motion.
The improved Engine is provided with a piston working in a Cylinder supplied
with steam by means of a distributing valve contained in a cylindrical case com-
municating with Steam Ports passages leading to the opposite ends of the Cylinder
This valve or slide is composed of two pistons each provided with a packing ring of
the requisite breadth to provide for the lap required to ensure the proper action of
the Engine. Webs or bara extending from one side to the other of the orifices or
ports in the valve case serve to guide the pistons and prevent the packing rings
from catching against the edges of the said ports or orifices.
The slide or piston valve is balanced live steam being admitted to tho space
between the pistons and leakage between the Pistons or Valves and the seating
constituted by the sides of the Cylindrical case is prevented by the spring packing
rings which are turned to a somewhat larger diameter than that of the Cylinder in
which they work.
The steam being admitted to the valve chest fills the space between the piston
valves which alternately uncover the ports or passages herein before referred to
leading to the steam Cylinder-The said ports or passages also serve as eduction
passages being placed by the slide at the proper time in communication with suit-
able exhaust passages arranged at the extremities of the valve chest.
The gear connected with the distribution the expansion and the governor
is composed of a small number of parts arranged as hereinafter described-Tho

page_text: eccentric is carried by a fly wheel or pulley is keyed on the crank shaft its position
relatively to the crank being adjusted according to the angle of the eccentric and
the direction in which the Engine is intended to work-The boss of this wheel or
pulley is provided on the side nearest to the Engine with a grooved or slotted plate
in which slides a corresponding projection or tongue on the eccentric operating the
sl de or distribution valve. In a prolongation above this groove or slot and inside
the drum or pulley there is provided a spring preferably composed of two blades
connected to the inside of the pulley and also to the eccentric To this spring is
attached a measured weight arranged inside the spring on the side nearest the
eccentric and the tension of the spring is regulated before hand in accordance with
the resistance to be overcome.
When the Engine is working at the normal speed the centrifugal force acting
upon the weight balances the tension of the spring. Under these conditions any
further increase in the speed increases the force exerted by the weight upon the
spring and shifts the eccentric along the groove or slot in the plate attached to the
boss of the fly wheel or pulley. This shifting of the excentric due to the increase
of centrifugal force shortens the stroke of the slide and consequently also shortens
the duration of the admission of steam to the Cylinder and at the same time
increases the period of compression-The parts are so arranged that the angle of
the eccentric is changed at the same time that the length of the stroke is changed
and thus the lead at admission is rendered constant and never. varies It is thus
rendered possible to pass from the position for maximum supply to that of minimum
supply with any predetermined variation in the speed however sinall.
The weight acts directly on the excentric without the intervention of any
intermediate parts and acts with considerable power.
In order that the Governor may not be liable to shift the eccentric too quickly
when the load on the Engines is suddenly removed or put on, a dash pot or
Cataract arrangement is employed preferably consisting of a piston connected to
the eccentric and working in a Cylinder containing a liquid and so arranged that
when the piston moves in the Cylinder the liquid is driven out in front of the
piston and passes into the space behind the latter at the same time presenting a
certain amount of resistance to the motion of the piston, which resistance may be
increased or diminished as required according to circumstances by contracting the
passage and thus retard the motion of the eccentric.
T

page_text: Improvements in Steam Engines.
I JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of said Invention for IMPROVEMENTS - IN
STEAM ENGINES which Invention has been communicated to me from abroad by
Messieurs Lecouteux and Garnier of Paris in the Republic of. France Mechanical
Engineers and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :—
This Invention has for its object providing an engine suitable for transmitting
motion directly to machines requiring to be driven at a high rate of speed such as
dynamo or magneto electric machines fans circular saws and the like "Machines of
this description are usually driven by means of multiplying gear or counter shafts
and belting interposed between the machinery and the motor in order to allow the
driving shaft of the motor engine to move more slowly than the machine driven
because it has heretofore been found impossible to construct a motor capable of
working in practice at a very high rate of speed for the following reasons
first place sufficient attention was not paid to the extraordinary strain on the
working parts of engines of this class and secondly the difficulties of providing
for a simple and effectual means for expansion and for a governor which would not
with sufficient quickness upon the motive fluid were found insurmountable.
In the
The Engine constructed according to this Invention is designed to comply with
the necessary conditions for working at high speeds being arranged to occupy
a small space and being devoid of any complicated parts. The number of working
parts is reduced to a minimum and provision is made for varying the expansion by
the action of the governor which is made very sensitive and powerful in order to
enable it to act instantaneously upon the valve or expansion gear being composed
of strong parts acting directly one upon the other.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 of the accompanying Drawings represents a vertical section of an engine
constructed according to this Invention and figures 2. 3. 4 and 5 illustrate details
hereinafter explained.
This Engine is provided with a piston H working in a cylinder G supplied with
steam by means of a distributing valve contained in a case composed of a cylin-
drical body A A' communicating with steam passages B B' leading to the opposite
ends of the cylinder.
This valve or slide is composed of two pistons C. C each provided with a packing
ring DD' of the requisite breadth to provide for the lap required to ensure the
proper action of the engine,
Webs or bars E E E E extending from one side to the other of the orifices or
passages B B¹ serve to guide the pistons C. C¹ during the whole of their stroke
and prevent the rings D'D' from catching against the edges of the said passages
or orifices

page_text: This slide or piston valve is a balanced valve live steam being admitted to the
space between the pistons C C and leakage between the said pistons and the seating
constituted by the sides of the cylindrical case A is prevented by the rings D D¹
"which are turned to a somewhat larger diameter than that of the cylindrical case
in which they work.so as to cause them to press by their elasticity against the
surface thereof and form a tight joint in a similar manner to the packing rings
of the working pistons in ordinary steam engines The steam enters a space or
chamber F whence it passes alternately through the passages B and B¹ to the
steam cylinder G and acts upon the piston H The said ports or passages BB'
also serve as eduction passages being placed by the valve at the proper time in
communication with exhaust passages I 1' arranged at the extremities of the valve
chest.
The gear connected with the distribution the expansion and the governor is
composed of a small number of parts arranged as hereinafter described The slide
valve is worked by an excentric L carried by a drum or pulley J keyed on tho
crank shaft its position relatively to the crank being adjusted according to the
direction in which the engine is intended to work. The boss of this pulley is
provided on the side nearest to the engine with a grooved or slotted plate K
figures 1 and 3 in which slides a corresponding projection or tongue M on the
excentric.
A spring N is connected to the inside of the periphery of the pulley J and also
to the eccentric L as indicated in figures 1 and 2-To this spring is attached a
measured weight O arranged inside the spring on the side nearest the excentric
the tension of the spring being regulated before hand in accordance with the
resistance to be overcome.
When the engine is working at the normal spoed the centrifugal force acting
upon the weight O balances the tension of the spring N Under these conditions
any farther increase in the speed increases the force exerted by the weight O upon
the spring N and shifts the excentric along the groove in the plate K This shifting
of the excentric due to the increase of the centrifugal force shortens the stroke of
the slide valve and consequently also shortens the duration of the admission of
steam to the cylinder and at the same time increases the period of compression
The parts are so arranged that the angle of the excentric is changed at the same
time that the length of the stroke is changed and thus the lead at admission is
rendered constant and never varies-It is thus rendered possible to pass from the
position for maximum supply to that of minimum supply with any predetermined
variation in the speed however small.
The weight O acts directly on the excentric-L without the intervention of any
intermediate parts and acts with considerable power its action being dependent
only on the value of the weight O and the resistance of the spring N. The value
or measure of the weight and the tension of the spring are directly related and
bulance or counteract one another according to the speed of the engine.
In working with high speed steam engines especially when they are connected
directly to dynamo or magneto electric machines it occasionally happens that when
the current is suddenly interrupted or suddenly turned full on without graduating
the action, the resistance opposed to the engine is very suddenly increased or
diminished and the speed changes accordingly with great suddenness so that
a governor arranged to act with such force as the one hereinbefore described is
liable to act instantaneously and sometimes with such power that the admission
is suddenly increased or diminished without passing through the intermediate
degrees thus causing the engine to run irregularly until it settles down to the
normal speed. In order that this governor may not be liable to shift the excentric
too quickly when the load on the engine is suddenly removed or put on, a dash pot
or cataract G (shewn on a larger scale in Section in figure 4 and in end elevation
in figure 5) is employed. This cataract is provided with a piston connected by a
rod T to the excentric L and working in a cylinder U attached to the pulley J.
This cylinder contains a liquid and is so arranged that when the piston moves in

page_text: the cylinder the liquid is driven out in front of the piston and passes along a
passage W, into the space behind the latter at the same time presenting a certain
amount of resistance to the motion of the piston, which resistance may be
increased or diminished by regulating the area of the passage so as to retard the
motion of the excentric as required. The effect of this arrangement is that the
action of the governor is enabled to be regulated in such a manner as to cause it
to require a certain time for shifting the excentric from. minimum to maximum
admission or vice versa, and thus compel the admission to pass gradually through
all the intermediate stages or degrees so that the speed and power of the engine
are not subject to too sudden and violent changes.
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
First. The general construction and arrangement of parts constituting the
improved steam engine herein before described the said engine being provided with
a balanced slide valve and means for automatically controlling or regulating the
admission of steam to the working cylinder substantially as herein before described
with reference to the accompanying drawings.
Second. A steam engine provided with a balanced piston slide valve having
rings D. D¹ for preventing leakage at the steam orifices substantially as hereinbefore
described and illustrated in figure 1 of the accompanying drawings.
Third. A steam engine provided with an eccentric and means for automatically
changing the stroke or throw and angle of the said excentric for the purpose of
enabling the degree of introduction expansion and compression of the steam to be
varied instantaneously and at the same time preserving a constant lead at admis-
sion substantially as hereinbefore described and illustrated in the accompanying
drawings.
Fourth. A steam engine provided with a governor acting by centrifugal force
opposed to a blade spring the said governor being connected directly to tho
excentric so as to shift the latter in such a manner as to regulate or control the
power exerted by the engine with rapidity and precision substantially as herein-
before described and illustrated in the accompanying drawings.
Fifth.―The steam engine governor referred to in the preceding claiming clause
in combination with an adjustable excentric and a balanced slide valve provided
with rings D D' substantially as herein before described and illustrated in the
accompanying drawings.
Sixth. The combination in a high speed steam engine of the improved governor
acting by centrifugal force opposed to a blade spring as hereinbefore described and
claimed and a cataract or dash pot presenting an adjustable resistance to the action
of the said governor substantially as herein before described and illustrated in the
accompanying drawings.