IMPROVEMENTS IN INDICA- TORS USED FOR ASCERTAINING THE POWER OF STEAM AND OTHER ENGINES
Year: 1878

page_text: LETTERS PATENT to John Richardson, of 64, Torreano Avenue, Camden Town,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN INDICA-
TORS USED FOR ASCERTAINING THE POWER OF STEAM AND OTHER ENGINES."
Sealed the 22nd November 1878, and dated the 13th July 1878.
PROVISIONAL SPECIFICATION left by the said John Richardson at the
Office of the Commissioners of Patents on the 13th July 1878.
JOHN RICHARDSON, of 64, Torreano Avenue, Camden Town, in the County of
Middlesex. "IMPROVEMENTS IN INDICATORS USED FOR ASCERTAINING THE POWER
OF STEAM AND OTHER ENGINES."
Heretofore in the ordinary diagram indicator apparatus for recording the pressure
in the cylinder of a steam or other engine throughout the stroke, the paper on which
the diagram is to be obtained has been clamped or clasped on to the surface of a
cylinder which has been revolved with a to-and-fro oscillatory motion imparted by
the to-and-fro motion of the piston.
According to my Invention I provide means for shifting the strip of paper a
distance endwise around the cylinder as each diagram is taken, so that after a
diagram has been taken for one stroke another diagram may be taken for the next
stroke, but on a different part of the strip; thus a number of diagrams of the ordi-
nary character may be taken one after the other for successive strokes of the engine,
and the diagrams may be at any desired distance, and overlap one another to any
extent that may be convenient. For this purpose I form the strip of paper on.
which the diagrams are to be obtained into a roll, and place it into a tubular
receptacle within the interior of the cylinder. Down the side of the tubular recep-
tacle is a slit through which the end of the paper is led; afterwards the paper is
passed through a slit in the side of the cylinder, then around the cylinder, and back
again through the slit into the interior of the cylinder, where it is secured to a roller
on to which it can be wound from time to time as each diagram is taken.

page_text: To effect the turning of the roller I secure to the axis of the roller a small pinion
which gears with another pinion that can turn freely around the axis of the cylinder.
On this latter pinion is a small ratchet wheel into the teeth of which enters a small
pawl carried by a stationary arm or link; thus, whenever the cylinder turns in one
direction the paper is wound up a distance on to the roller, but when the cylinder
turns in the opposite direction the pawl slips over the ratchet teeth, and no winding
up takes place.
The automatic moving forward of the paper around the cylinder can instanta-
neously be arrested by lifting away the stationary arm or link that carries the pawl
and the ratchet wheel with which it works.
In order to cause the pencil or marker of indicator diagram apparatus to move
up and down in a straight line, and at the same time give it a certain amount of
freedom, so that it shall bear uniformly against the paper to be marked, I pass the
pencil or marker loosely through a small slide which can rise and fall in a fixed
straight guide, the pencil is also connected by links to the lever arms, which are
coupled to the piston rod of the pressure indicator apparatus. Thus the guide
compels it to move in a straight line whilst it can spring backwards somewhat
through the guide, so as to allow it to press uniformly against the paper.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Richardson in the Great Seal Patent Office on the 13th January
1879.
JOHN RICHARDSON, of 64, Torreano Avenue, Camden Town, in the County of
Middlesex. "IMPROVEMENTS IN INDICATORS USED FOR ASCERTAINING THE POWER
OF STEAM AND OTHER ENGINES."
Heretofore in the ordinary diagram indicator apparatus for recording the pressure
in the cylinder of a steam or other engine throughout the stroke, the paper on which
the diagram is to be obtained has been clamped or clasped on to the surface of a
cylinder which has been rèvolved with a to-and-fro oscillatory motion imparted by
the to-and-fro motion of the piston.
According to my Invention I provide means for shifting the strip of paper a
distance endwise around the cylinder as each diagram is taken, so that after a
diagram has been taken for one stroke another diagram may be taken for the next
stroke, but on a different part of the strip; thus a number of diagrams of the ordi-
nary character may be taken one after the other for successive strokes of the engine,
and the diagrams may be at any desired distance, and overlap one another to any
extent that may be convenient. For this purpose I form the strip of paper on
which the diagrams are to be obtained into a roll, and place it into a tubular recep-
tacle within the interior of the cylinder. Down the side of the tubular receptacle
is a slit through which the end of the paper is led; afterwards the paper is passed
through a slit in the side of the cylinder, then around the cylinder, and back again
through the slit into the interior of the cylinder, where it is secured to a roller on
to which it can be wound from time to time as each diagram is taken.
To effect the turning of the roller I secure to the axis of the roller a small pinion
which gears with another pinion that can turn freely around the axis of the cylinder.
On this latter pinion is a small ratchet wheel into the teeth of which enters a small
pawl carried by a plate, arm, or link that can be held stationary; thus, whenever the
cylinder turns in one direction the paper is wound up a distance on to the roller, but
when the cylinder turns in the opposite direction the pawl slips over the ratchet
teeth, and no winding up takes place.
The automatic moving forward of the paper around the cylinder can instanta-
neously be arrested by releasing or lifting away the plate, arm, or link that carries
the pawl and the ratchet wheel with which it works.
In order to cause the pencil or marker of indicator diagram apparatus to move up
and down in a straight line, and at the same time give it a certain amount of
freedom, so that it shall bear uniformly against the paper to be marked, I pass the
pencil or marker loosely through a small slide which can rise and fall in a fixed
straight guide; the pencil is also connected by links to the lever arms, which are
coupled to the piston rod of the pressure indicator apparatus. Thus the guide
compels it to move in a straight line, whilst it can spring backwards somewhat
through the guide, so as to allow it to press uniformly against the paper.
Having thus described the nature of my Invention, I will proceed to describe
more fully the manner of performing the same.
In the Drawings hereunto annexed,
Figure 1 shews.a side elevation, and Figure 2 a plan view, with part removed, of
an indicator apparatus constructed, as above described, in such a manner as to allow
of a number of diagrams of the ordinary character being taken continuously for
successive strokes of an engine of a strip of paper, the diagrams overlapping one
another to any extent desired.
Figure 3 shew's separately a horizontal section of the oscillating cylinder.

page_text: In these Figures A is the oscillating cylinder containing a coiled spring in its
lower part A¹, which spring tends to turn the cylinder in one direction; B is a cord
secured to and wound around the cylinder, and by this cord, which is to be attached
to a reciprocating part of the engine, the cylinder can be turned in the opposite
direction, as in ordinary indicator apparatus. C is the steam cylinder of the appa-
ratus, which can be coupled up to a cock in connection with the steam cylinder of
an engine by a union C¹ in the ordinary manner. In the cylinder is a piston; the
piston rod passes out through the cover of the top of the cylinder. Around the
piston rod is a coiled spring; the lower end of the spring is secured to the piston rod,
and its upper end to the cylinder_cover. On the top of the piston rod is a swivel
connected by short links to links D, which as the piston rises or falls cause a pencil
The
or marker E to move up and down in a straight line in any ordinary manner.
arms F which carry the pivots of the links are carried by a tube G; this tube can
turn freely around the steam cylinder C, so that the pencil or marker E can be
moved away from the paper on the oscillating cylinder A, as is usual in indicator
apparatus heretofore constructed. E¹ is another metallic pencil or marker carried
by a slide which can be clamped in any desired position to the upright rod H, also
carried by the tube G. This pencil or marker is set at the same level as the point
of the pencil or marker E when the under side of the piston of the steam cylinder
is not acted on either by pressure or vacuum, and serves to mark the atmospheric
line on the diagram paper.
.
In Figure 1 the pencils or markers are shown turned away from the paper on the
oscillating cylinder A, and out of action.
In Figure 2 they are shown bearing against the paper, and in position for
marking diagrams upon it.
As before stated, in ordinary indicator diagram apparatus the paper on which the
diagram is to be taken is merely clipped around the circumference of the oscillating
cylinder, but by my improvements I am enabled intermittently to shift the paper
around the circumference of the cylinder, and take successive diagrams of the ordi-
nary character overlapping one another for successive strokes of an engine.
I will now describe more fully the manner in which this is effected.
In the cylinder A is a longitudinal slit, with a roller J at each edge; parallel with
and near to each of these rollers is another roller I pressed by springs K against the
exterior of the cylinder. L is a roll of paper contained within a tubular casing M
in the interior of the cylinder; the end of the roll of paper is led through a slit in
this tubular casing, out through the slit in the cylinder A, and under one of the
rollers I; then around the cylinder, and under the other roller I, and again into the
cylinder to a spindle N, on to which it can be wound. The spindle N has a longi-
tudinal slit formed through it through which the end of the paper is passed for the
purpose of fastening the paper to the spindle. On the top of the spindle is a toothed
wheel O, and below this a small spring to apply friction and prevent the spindle
from turning to freely. The toothed wheel O gears into another toothed wheel P,
capable of turning freely in one direction around the axis of the cylinder A. This
toothed wheel turns upon a hollow spindle carried by a plate Q, notched around its
circumference. This plate and the toothed wheel carried by it are shown separately
at Figures 4 and 5. R is a catch, which can either be turned up as shown by full
lines in Figure 1 into a position to enter one or other of the notches in the circum-
ference of the plate Q, and so prevent this plate from turning, or can be turned
down into the position shown by the dotted line, and set the plate Q free to turn
The toothed wheel P carries a ratchet wheel P¹ with the teeth of which a pawl R
acted on by a spring R2, engages (as is shewn in the under side view of part of the
plate Q at Figure 4*) the pawl, allows the wheel to turn in one direction when the
plate Qis held fast, but prevents its turning in the other direction.
When a succession of partially overlapping diagrams are to be taken the plate Q
is held from turning by the catch R, and the pencils or markers are brought, as

page_text: shown at Figure 2, against the paper which surrounds the cylinder A. When the
cylinder is turned in one direction the pencils or markers record on the paper the
varying pressures in the cylinder of the engine on one side of the piston, just as
with an ordinary diagram indicator apparatus. When the cylinder is turned in the
opposite direction the variations in the pressure at this end of the cylinder are again
recorded, whilst at the same time by reason of the toothed wheel P being by the
action of the ratchet pawl prevented from turning the toothed wheel O on the
spindle N is caused to turn, and by turning the spindle winds up a portion of paper
on to it; thus at each back stroke or return oscillation of the cylinder A the paper
is moved forward a distance, and the diagrams are taken continuously for successive
strokes of the engine.
Figure 6 shows a sample of a succession of diagrams thus taken from a con-
densing engine.
Figure 7 shews a similar succession of diagrams taken from a locomotive non-
condensing engine.
In these diagrams X, Y, shews the atmospheric line.
The other part of my Invention, which relates to improved means for causing the
pencil or marker of diagram indicator apparatus to move to and fro in a straight
line, and yet enable the marker a certain amount of play, so that its point shall be
able to bear uniformly against the paper to be marked, is illustrated at Figures 8
and 9.
G is a tube capable of swivelling around the steam cylinder of the apparatus as
usual. D, D, are arms connected by a swivel joint to the top of the piston rod of
this cylinder. D¹ are links which connect the ends of these arms to the pencil or
marker E. The point of the pencil passes freely through a small slide S which can
move up and down along a straight slot in a plate T as shown. The spring of the
links D, D', keeps the point of the marker pressing with a uniform pressure against
the surface to be marked, whilst the slide S compels the pencil to move up and down
in a straight line.
The pencil or marker shown in the Drawing consists of a small metallic rod
carried by a screw which screws into a distance piece D³, by which the ends of the
links D¹ are kept at a distance apart from one another.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I am aware that it has before been pro-
posed to construct diagram indicator apparatus in such a manner that continuous
diagrams for successive strokes of an engine may be taken by causing a strip of
paper on which the diagrams are to be marked to move continuously in one direc-
tion past the pencil or marker of the apparatus, I however make no claim to
constructing diagram indicator apparatus for ascertaining the power of steam and
other engines in such a manner that a continuous series of diagrams for successive
strokes of an engine can be thus taken, but I claim,―
First. Forming the oscillating cylinder of diagram indicator apparatus in such a
manner that a roll of paper may be carried within it and the end of the roll, be led
out through a slit in the cylinder, then around the cylinder, and in again through
the slit to a roller in the interior of the cylinder, on to which roller the paper can be
wound whenever it is required to move it forward a distance.
Second. Forming diagram indicator apparatus in such a manner that the paper
carried by the oscillating cylinder of the apparatus can be unwound from one roll
and wound up on to another roll, and so moved step by step over the surface of such
cylinder, substantially as herein-before described.
Third. Forming indicator apparatus used for ascertaining the power of steam and
other engines, substantially in the manner herein-before described, and illustrated at
Figures 1 to 7 of the Drawings annexed.
Fourth. The means of ensuring that the pencil or marker of indicator apparatus
used for ascertaining the power of steam and other engines shall move to and fro in
a straight line, and yet be free to bear uniformly against the surface upon which the

page_text: diagram is to be marked, substantially as herein-before described, and illustrated at
Figures 8 and 9 of the Drawings.
In witness whereof, I, the said John Richardson, have hereunto set my hand
and seal, this Thirteenth day of January, in the year of our Lord One
thousand eight hundred and seventy-nine.
JOHN RICHARDSON. (L.S.)