IMPROVEMENTS IN AND CONNECTED WITH STEAM ENGINE INDICATORS
Year: 1880

page_text: LETTERS PATENT to Lykke Boye, of Bergen, Norway, but at present of
Dumbarton, in the County of Dumbarton, Scotland, for an Invention of
"IMPROVEMENTS IN AND CONNECTED WITH STEAM ENGINE INDICATORS."
PROVISIONAL SPECIFICATION left by the said Lykke Boye at the Office
of the Commissioners of Patents on the 14th June 1880.
LYKKE BOYE, of Bergen, Norway, but at present of Dumbarton, in the County of
Dumbarton, Scotland. "IMPROVEMENTS IN AND CONNECTED WITH STEAM ENGINE
INDICATORS.
In indicators as heretofore constructed the steam pressure acting on a piston,
Bourdon spring, or diaphragm spring, gives motion to the indicating point through
an arrangement of levers, and the indicating point is brought in contact with
a card which is bent round a drum, receiving an oscillating motion by means of
a cord pulled by the engine against a spring.
This arrangement is faulty, because the inertia and momentum of the piston,
levers, and cord seriously affect the sensibility of the action of the instrument,
which can thus only give a very incorrect indication of the work done in the
cylinder, and it is inconvenient because it is not easily worked by the engineer.
In my Invention theso difficulties are overcome.
Now, according to my Invention, the card drum receives an oscillating motion
from a helical or spiral spring tube. This tubo is attached to the ends of the
steam cylinder. When in use the card drum turns about its axis in proportion to
the degree of pressure or vacuum in the cylinder, and consequently also in the
spring tube aforesaid. The helical or spiral tube may be readily exchanged for a
stronger or weaker spring, and a set of two or more answering to different pressures
may be provided for each instrument.
1 attach the indicating point to a mechanism which receives motion from the
engine.
Although I might use any convenient arrangement for this purpose, I prefer a
bar which moves the indicating point in a direction parallel with the axis of the
drum, wheroby a diagram is obtained representing correctly the performance of
work done in the steam cylinder..

page_text: The indicating point might be so connected to the bar that at the end of each
revolution it is shifted in a convenient direction across the card; thus a successive
number of diagrams are taken on one card without stopping the instrument or
removing the card; or the indicating point may be fixed and the card drum
similarly shifted with the same object.
In connection with the indicator I may arrange a "mean prossure recorder," which
consists of a mechanism the movements of which every moment will be a function
of those movements which produce the indicator diagrams, and which has a dial
so arranged that the mean pressure of each diagram can easily be read off.
"
I may also connect therewith a "minute revolution counter" to receive motion
from the bar or other mechanism moving the indicating point.
The counter" is fitted with a mechanism which is regulated by an
"escape
movement" or other mechanical equivalent, so that at the end of a convenient
number of minutes it is detached and the revolutions are easily read off on a
dial.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Lykke Boye in the Great Seal Patent Office on the 11th December
1880.
LYKKE BOYE, of Bergen, Norway, but at present of Dumbarton, in the County of
Dumbarton, Scotland. "IMPROVEMENTS IN AND CONNECTED WITH STEAM-ENGINE
INDICATORS."
In indicators as heretofore constructed the steam pressure acting on a piston
against a helical spring, Bourdon brass tube, or diaphragm spring, gives motion to
the indicating point through an arrangement of lovers, and the indicating point is
brought in contact with a card which is bent round a drum, which receives an
oscillating motion from a cord pulled by the engine against a spiral spring.
This arrangement is faulty, because the working of the springs, the momentum
of inertia, and the friction of the piston, levers, druin, and cord seriously affect the
sensibility of the action of the instrument, which can thus only give a very
incorrect indication of the work done in the cylinder; it is inconvenient because it
is not easily worked by the engineer.
In my Invention these faults and difficulties are overcome. According to my
improvements the surface on which the diagrams are drawn receives from the steam
of the steam cylinder an oscillating motion exactly proportionate to the degree of
pressure or vacuum in the cylinder, and the indicating object by which the
diagrams are drawn is attached to a mechanism which receives from the engine a
motion exactly answering to that of the piston in the steam cylinder.. Two move-
ments are thus obtained, which combined give a. diagram correctly representing

page_text: the performance of work in the steam cylinder, which it has been impossible to
obtain with indicators heretofore constructed.
The indicating object may be so connected to the mechanism from which it
receives its movement that it can be shifted in a convenient direction across the
surface on which the diagrams are drawn, so that a continuous number of diagrams
may be obtained on that surface without removing it or stopping the instrument;
or the indicating object may be fixed and the surface upon which the diagrams are
to be drawn shifted to obtain the same result.
"
In connection with the indicator I may arrange a mean pressure recorder,"
consisting of a suitable mechanism the movements of which will be a function of
those movements which produce the indicator diagrams, an index being so
arranged that the mean pressure or the whole area of each diagram can easily be
read off.
But to make my Invention better understood I will proceed to describe the
same by reference to the accompanying Drawings, which represent a suitablo
method of practically realizing the principles involved in my Invention.
"
"
Figure 1, Sheet 1, shews a sectional elevation, and Figure 4, Sheet 1, a plan of
the indicator with a mean pressure recorder" attached; and Figure 2, Sheet 2,
shews an elevation, and Figure 3, Sheet 2, a plan of the indicator without a
pressure recorder," Figure 5, Sheet 1, detail. Similar letters in all the Figures
represent similar parts.
mean
A is a standard, to which is attached the various parts of the instrument; B is
a nozzle, one ond of which is connected by means of a screw C to the steam
cylinder in the usual manner, the other end of which is attached to a spring steel
tube D, which is connected with the card drum segment F by means of a connecting
link E. The steel tube may be readily exchanged for a stronger or weaker one as
desired, and a set of two or more answering to different initial steam pressures may
be provided for each instrument. The drum segment F moves on two points,
which are adjustable, and has a suitable card holder at the sides to secure the cards
to the drum; G is a rod which fits inside the standard A; H is an arm firmly
fixed to the rod G, and forms a guide in the lower part of the standard to prevent
The
it moving sideways; I is a standard securely fixed to the arm H by a nut.
arm H, the rod G, and the standard I are attached to an oscillating part of the
engine by means of a connecting rod R; K is a socket which slides in the
standard I, and is moved up and down by means of a screw and nut L; M is a
lover fitted to the socket K, so that it may be moved about ninety degrees in a
backward direction in order that the cards may be easily removed; the other end
of the lever is arranged to carry an indicating point, which is lightly beld against
the card by small springs. Should it be preferred to employ liquid in lieu of a
pencil to mark the diagram, I may so construct the standard I that it will be
suitable for this purpose; N is the "mean pressure recorder," which receives
motion from a plate on the card drum F when this moves according to the
expansion, exhaust, and compression of the steam in the cylinder and from the
rod G which derives its motion from the engine. In the "mean pressure recorder,"
which is constructed on the principle that all diagrams, according to my Invention,
have the same fixed length whatever speed and stroke the engine may have. a is
the measuring wheel, which receives its reciprocating motion from tho quadruplo
threaded rod G, nut O, and links d, d, such that it turns about a fixed axis within
an angle of ninety degrees, and which receives a rotary motion from the segment F
when the expansion of the steam in the cylinder is beginning, or in the case of
The amount of the
non expansion cylinders by the beginning of the exhaust.
rotary motion will depend on the nature of those curves which together make out
a diagrain, or (what is the same thing) will depend upon the relative movement of
the drum and the rod G; b, pair of bevil wheels which transmit the notion of tho
5 wheel a to the index plate c, the index of which may easily be fixed by empirical
experiments; c.g., a whole revolution of the index plate c, equal to the mean
ordinate in a diagram with a constant pressure of one hundred pounds (the exhaust

page_text: not being taken into consideration), and length equal to the fixed stroke of the
indicator, consequently a whole revolution of the index plate c represents a mean
pressure of one hundred pounds; for other diagrams of the same fixed length the
recorder gives their respective mean ordinates; d, d, are connecting links which
transmit the motion of the quadruple threaded rod G and nut O to the frame c
The whole "mean pressure recorder" may be easily removed out of the bracket f
in which it reciprocates.
Having thus described the nature of my Invention, and a suitable manner of
performing the same, what I claim is,―
Firstly. The general arrangement and construction of the improved stean
engine indicator, as hereinbefore described and represented in the accompanying
Drawing.
Secondly. In an indicator for steam engines the moving the surface on which
diagrams are drawn by means of the steam from the steam engine, as herein before
described.
Thirdly. In an indicator for steam engines the moving the indicating object
by means of a suitable mechanism attached to the engine, as heroinbefore
described.
Fourthly. In an indicator for steam engines the shifting the indicating object,
so that a number of diagrams may be inscribed upon the same surface without
removing it from the instrument, as hereinbefore described.
Fifthly. The tube, made of steel, with a section equal or similar to that shewn
in the Drawing, and fitted with a suitable valve for cleaning purposes when
desired.
Sixthly. Attaching when desired to an indicator constructed as hereinbefore
described, a suitable mechanism whose movements shall be a function of those
movements which produce the indicator diagram, and which shew on an index the
mean pressure of diagram of the same length or the areas of diagrams differing in
length, as herein before described.
In witness whereof, I, the said Lykke Boye, have hereto set my hand and
seal, this First day of December, in the year of our Lord One thousand
eight hundred and eighty.