IMPROVE- MENTS IN INDICATORS FOR STEAM AND OTHER ENGINES
Year: 1881

page_text: LETTERS PATENT to Arnold Budenberg, of the City of Manchester, in the
County of Lancaster, Mechanical Engineer, for an Invention of "IMPROVE-
MENTS IN INDICATORS FOR STEAM AND OTHER ENGINES." A communication
from abroad by Christian Frederick Budenberg and Bernhard August Schaeffer,
PROVISIONAL SPECIFICATION left by the said Arnold Budenberg at the
Office of the Commissioners of Patents on the 12th October 1881.
ARNOLD BUDENBERG, of the City of Manchester, in the County of Lancaster,
Mechanical Engineer. "IMPROVEMENTS IN INDICATORS FOR STEAM AND OTHER
ENGINES." [A communication from abroad by Christian Frederick Budenberg
and Bernhard August Schaeffer, of Buckau Magdeburg, in the German Empire.]
This Invention has for its object the production of diagrams which shall show
in one figure the amount of work done in a complete double stroke of a steam or
other engine in addition to all the particulars which may be derived from the
diagrams produced by the indicators in general use. The complete diagrams
produced by means of these improvements possess the further advantage of not
requiring correction for barometrical variations.
These improvements consist in providing two separate steam inlets and cylinders
or chambers in the indicator, one of which is in communication with one end of
the engine cylinder, the other being in communication with the opposite end of the
engine cylinder by means of suitable pipes. These pipes are provided with taps
or valves for the purpose of controlling the passage of the steam therein. A drum
is provided, as in ordinary indicators, for carrying the card on which the diagram
is traced, and the tracing pencil is actuated through suitable link work by the
piston rod or its substitute.
In the first arrangement of the apparatus two cylinders are bored at opposite
ends of a pipe having cast midway in its length a diaphragm or partition, which
divides the pipe or tube into two portions. Čast with the body of the pipe there

page_text: are also two steam inlets, one communicating with the space below and the other
with the space above the diaphragm. Two pistons are accurately fitted into the
cylinders above the steam inlets, and both these pistons are mounted on one rod
which passes through the diaphragm. The piston rod is prolonged above the upper
piston and communicates with the link work. The spiral springs are placed 5
between the pistons and the diaphragm.
In the second arrangement two cylinders are provided having a common axis
and a short interval of space between their contiguous open ends. The outer ends
of these cylinders are closed to the air, and are each provided with a steam inlet.
A piston is fitted into each of the cylinders, and both are mounted upon a piston 1
rod. Upon the centre of the rod is fixed a collar carrying an arm which commu-
nicates the motion to the linkwork. The spiral springs may be placed either
between the pistons and the outer ends of the cylinders, or they may be placed
between the pistons and the collar on the middle of the piston rod.
In the foregoing arrangement one spiral spring instead of two may be employed
in the following manner:-The piston rod is prolonged and is enclosed by a casing,
within which at a distance from each other corresponding to the length of the
spring are two annular projections. Upon the piston rod at the same distance
apart are secured two collars. The spiral spring is placed between the two annular
projections and is provided at each end with a flanged sleeve, the flanges of which
abut against the inner sides of the annular projections. By this arrangement, in
whichever direction the piston rod is moved, the collar upon it bears upon and
compresses the spiral spring, the opposite end of which is supported by the further
annular projection. If it is desired to use the spiral spring in tension instead of in
compression a slight modification is necessary.
The piston rod is prolonged and surrounded by a casing, as in the previous
instance. This casing for a length corresponding to the length of the spiral spring
may form a closed tube, but beyond this distance it is slotted at each end with
diametrically opposite slots. The sleeve at each end of the spring has formed
upon it two wings, which fit into and work in the slots. The piston rod has fixed
upon it two collars of a smaller diameter than the internal diameter of the spring,
in such positions that they shall each be in contact with the inner surface of one
of the sleeves. In whichever direction then the piston rod is moved one of the
collars is pressed against one of the sleeves and the spring is put in tension, the
opposite end of the spring being supported by the wings on its sleeve resting
on the ends of the slots, the collar at that end being free to pass within the
spring.
In the third arrangement one piston only is employed, with two spiral springs,
one of which is used in tension and the other in compression. When at rest the
piston occupies the centre of a closed cylinder having a total internal length equal
to the united lengths of the two spiral springs and the thickness of the piston.
The two steam inlets are placed at the sides of the opposite extremities of the
cylinder and the spiral springs are placed between the piston and the cylinder
ends. The piston rod is prolonged so as to pass through one or both ends of the
cylinder, and the linkwork actuating the pencil is attached to one of the projecting
ends of the piston rod.
In the fourth arrangement two separate cylinders are placed side by side, each o
the cylinders being provided with a piston, spiral spring, and steam inlet below th
piston. The spiral springs may be both below or both above the pistons, or on
may be below one piston and the other may be above the other piston. The pisto
rods may be connected to the two ends of an oscillating beam, from one extremity
of which motion is communicated to the link work, or they may be in direc
communication with the first member of the link work, or one of the piston rod
may carry the drum on which the card is placed, while the other piston rod carrie
the pencil.
In the fifth arrangement two diaphragms, such as are employed in the Schaeffe
gauge, are used instead of cylinders, pistons, and spiral springs. Each of thes

page_text: two diaphragms is enclosed within a circular chamber having a separate steam
inlet. The diaphragms are parallel and have their centres opposite to each other.
A rod connects the two diaphragms, passing through one of them and out through
the casing, its exposed end being connected with the link work. The steam inlets
are so arranged that the pressure acts alternately upon the contiguous or inner
faces of the diaphragms.
In the sixth arrangement two chambers are provided in a right line with each
other, each having a separate steam inlet. Into each of these chambers is secured
a bent metallic tube having its outer end closed and similar in all respects to the
tube of a Bourdon gauge. These tubes are so arranged that their free ends oppose
each other. Upon the upper end of the two chambers, and immediately below the
free ends of the bent tubes, a stalk is cast and bored out for the reception of a
spindle. This spindle has secured to it the free ends of the tube and at its upper
end it is attached to the link work.
In order to provide for the adjustment of the drum, which carries the card to
any desired height, the drum is made in two portions, the outer one of which
slides upon the other. The inner portion of the drum is secured to the cord
pulley, upon the centre of which a stem is cast. The upper portion of this stem
carries the spring box, the cover of which has a projection bored and tapped for
the reception of a screw, which works in bearings on the upper end of the drum
and has motion imparted to it through the intermediary of a milled nut or like
contrivance. This improvement may also be applied to indicators of ordinary
construction.
In indicators constructed as hereinbefore indicated, if both the controlling taps
or valves are opened and the indicator is put in operation, a closed curve is produced,
one half of which is below and the other half above the atmospheric line. This
curve shows the total effective pressure, or in other words the total force, minus
the back pressure, and the total work done through a complete revolution or double
stroke.
By closing one of the controlling valves or taps a separate diagram may be
obtained for each end of the engine cylinder at will. If such separate diagrams and
a combined diagram are taken on the same card a graphic result is obtained, which
will give every required particular and greatly facilitate calculation and
deductions.
These improvements further consist in adding to the indicator a guide pulley for
the cord actuating the drum. Upon the bottom of the drum carrier is pivoted a
plate, which carries an arm upon which in turn is pivoted a carrier in which a
grooved pulley is mounted. The pulley arm is capable of being rotated, so that
the plane of the pulley may occupy any desired position. The plate bearing
the pulley carrier may also be rotated to any desired position around the
centre of the drum and is fixed in place by a wing screw or by similar
means.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Arnold Budenberg in the Great Seal Patent Office on the
12th April 1882.
ARNOLD BUDENBERG, of the City of Manchester, in the County of Lancaster,
Mechanical Engineer. "IMPROVEMENTS IN INDICATORS FOR STEAM AND OTHER
ENGINES." A communication from abroad by Christian Frederick Budenberg
and Bernhard August Schäffer, of Buckau Magdeburg, in the German Empire.
This Invention relates to indicators for steam and other engines, and has for its
object the production of diagrams which shall show precisely the amount of work
done during the double or forward and return stroke of the piston in addition to
al the other particulars usually shown by the diagrams of ordinary indicators.
It is customary in indicating engines to take separato diagrams for each end of
the steam cylinder, and in order to arrive at an approximate knowledge of the
state of the engine and of the work done, two distinct diagrams must be taken.
This involves either a duplication of the indicator or a considerable loss of time,
and the disadvantage that the two diagrams do not represent one revolution or
double stroke, but two halves of different revolutions. Further, the combined
diagrams can only be calculated by a complicated and approximate process.
This Invention consists in so constructing indicators that a combined diagram
from both ends of the cylinder may be taken at the same operation. This diagram
consists of a closed curve, one half of which is above and the other half is below
the atmospheric line. In addition, diagrams may be taken for each end of the
cylinder separately, and these separate diagrams will in every respect resemble
ordinary diagrams.
And in order that this Invention may be more readily understood and carried
into practical effect, I have hereunto appended a Sheet of Drawings illustrative of
the Invention, reference being had to such Drawings and the letters of reference
marked thereon. In all the views similar letters of reference are employed to
denote similar parts.
Fig. 1 shows a vertical section of the working part and elevation of the
recording part of one form of indicator to which the improvements are applied.
Instead of an ordinary single way steam inlet, two independent steam inlets A, A¹,
are constructed capable of connection with two pipes communicating with opposite
These
ends of the cylinder of the engine by means of unions in the usual manner.
two inlets are separated within the body of the indicator by means of a diaphragın
or partition B, so that one communicates with the upper half of the indicator, and
the other with the lower half. The lower portion of the indicator consists of a
cylindrical casing accurately bored and fitted with a piston K'. The upper portion
is similarly bored and fitted with a piston K. Both of the pistons are secured to a
piston rod S which passes through the diaphragm B, separating the two steam
inlets. The recording portion of the instrument may be similar to that of the
existing forms of instrument; springs are fitted to the pistons in the ordinary
manner, one for each piston, or one spring may be made to serve for both pistons.
The pressure at one end of the cylinder operates the upper piston, and the pressure
at the other end of the cylinder acts upon the lower piston of the indicator, and
the distance of each half of the closed curve in the resulting diagram above and
below the atmospheric line shows the effective pressure; or in other words, the live
steam pressure, minus the back pressure, on the exhaust side.
The whole closed curve resulting from a complete revolution of the engine gives
a graphic representation of the work done during that revolution, and gives all the

page_text: desired information as to the state of the valves, piston, and cylinder in a more
convenient form and in such a manner that calculation is greatly facilitated. The
two steam pipes in communication with the steam inlets A, A¹, may each be
provided with a valve or tap, by opening or closing which separate diagrams may
be taken in the ordinary way from each end of the cylinder. A combination of
such separate diagrams with the diagram taken simultaneously from both ends of
the cylinder forms of a clear and instructive record of the state of the engine and
of the work done.
Figs. 2, 3, and 4 show modifications of the indicator. In Fig. 2 the oylindrical
portion of the instrument is open at each end, while the spring or springs are
contained within the steam space. The recording portion of the indicator is
actuated by the continuation L of the piston rod S.
Figs. 3 and 4 show another torm in which the steam inlets are at opposite ends
of the indicator, the space between the pistons being open to the air. The
recording motion is taken from the rod carrying the two pistons by means of the
linkwork L.
In Fig. 3 the springs are between the pistons and the ends of the indicator in
the steam space, but if preferred they may be placed around the piston rod, as
shown in Fig. 4, in the open part of the instrument.
Figs. 5 and 6 represent other arrangements of the spring action. In Fig. 5 the
piston rod S is surrounded with a casing within which are formed the snugs or
projections V, V₁. Upon the piston rod, at a distance apart equal to the distance
between V and V', are fixed the collars C, C, which are free to pass between the
projections V, V'. The spring is mounted on two rings which abut against the
collars C, C¹, and against the projections V, V. When the instrument is in
operation the reciprocating motion of the piston rod compresses the spring because
of the pressure of the collar C or C¹ on its contiguous ring, and the resistance
offered by the opposite abutment or projection V or VL. Compression of the spring
follows therefore in whichever direction the piston rod S moves. In Fig. 6 another
method of obtaining the same result is shown. The piston rod has collars C, 0¹,
formed or fixed upon it, as shown also in Fig. 5. These collars are of such a size
that they may move freely within the spirals of the spring within which they are
placed. The spring is carried by two rings X, X', through which the piston rod
passes. The casing around the spring is provided with slots T, T, T¹, T', within
which work projections formed upon the rings X, X'. The reciprocating motion
of the piston rod S in this case puts the spring in tension in whichever direction it
travels, because the collar C carries with it the ring X, while the ring X¹ is held
stationary by the contact of the projections formed thereon with the bottom of
the slots T, T¹.
Fig. 7 shows a form of the indicator in which only one piston is used. The
steam ways are at opposite ends of the indicator, the central portion of which is
fitted with the piston K. Two springs are used, one on each side of the piston.
The piston rod passes through one or both ends of the casing and the link work is
attached to one of the ends L.
Figs. 8, 9, 10, 11, and 12, show different methods of obtaining the same result
with two cylinders and two pistons, the cylinders being vertical and parallel, and
each being provided with a steam inlet A, A¹, communicating with opposite ends
of the engine cylinder. In Figs. 8 and 9 the springs, one to each piston, are placed
between the piston and the cylinder covers, but they may be placed below the
piston, as shown in Fig. 10. The motion of the pistons may be transferred to the
recording portion of the apparatus either by the method shown in Fig. 8, or by that
shown in Figs. 9 and 10. In Fig. 8 In Fig. 8 both pistons are coupled by means of
suitable connecting rods to the rocking lever R, which has its fulcrum in the centre
of its length. The link work is pinned to either end of the lever R, as shown at L.
In Figs. 9 and 10 the pistons are attached by connecting rods to a horizontal link.
One of the connecting rods is pinned to one end of the link, the other being also

page_text: pinned to the same link, which projects beyond the second connecting rod, the end
of it being pinned in its turn to a second link moving about the stationary pin P.
This rocking link has at its other end the member L of the recording motion pinned
to it.
Fig. 11 shows an arrangement similar to those already described and illustrated in
Fig. 8, 9, and 10, but having a different recording apparatus to those already in use.
The card drum is carried by the piston S, and the pencil by the other piston S¹.
Motion is imparted to the card drum from the engine in the usual manner, and
both piston rods may be supported by bearings not shown in the Figures. Instead
of both the springs being either above or below the pistons, as already described,
one of them may be above and the other below, as shown in Fig. 12.
Figs. 13 and 14 illustrate two other methods of obtainining a like result without
the use of cylinders or pistons. In Fig. 13 the steam inlets communicate with the
two inner surfaces of parallel Schaffer springs Y, Y¹, such as are used in pressure
gauges. These two springs are connected by means of the rod S passing through
the diaphragm B. The upper spring Y carries a connecting rod L which serves to
transfer the resulting motion to the linkwork of the recording pencil.
Fig. 14 shows an equivalent arrangement in which two Bourdon springs Y, Y¹,
are used instead of Schaffer springs. Two independent steam inlets A and A¹
communicate respectively with the interiors of the springs which are secured
opposite to each other on the steam chambers F, F¹. The other ends of the springs
are pinned together, and to the first member L of the linkwork of the recording
portion of the apparatus. A guide rod S is also secured to the ends of the springs
and helps to maintain their ends in a vertical line. This guide rod works in a
vertical and cylindrical recess bored to fit the rod in a projection cast or fixed upon
the centre of the upper surface of the steam chambers F, F'.
Having thus described the nature of the said Invention, as communicated to me
from abroad, and the manner in which the same may be performed, I desire it to
be understood that I do not limit myself to the precise details shown and described,
as the same may be varied without departing from the nature of the Invention,
but I claim,
First. In duplex indicators in which the action of both the working pistons
causes the tracing point or pencil to move in opposite directions, the arrangement
of the pistons and springs in such a manner that for the production of the diagram
above and below the atmospheric line the same measure of the energy is employed.
Second. The arrangement of two springs, as represented in Figs. 2, 3, and 4.
Third. The arrangement of the two cylinders and pistons in the manner
represented in Figs. 3 and 4, and the arrangement of the rod L connected to the
piston rod whereby the use of stuffing boxes is avoided.
Fourth. The application of the snugs or projections V, VI, on the spring casing
Fig. 5, or the projections on the rings X, X', Fig. 6, for indicators, with the parts C
and X which are at opposite ends of the spring, as shown and described.
Fifth. In duplex indicators, the arrangement shown in Fig. 8 of the two
cylinders side by side with their pistons connected by a lever or levers, or links,
whereby the motion of one is influenced by that of the other.
Sixth. In duplex indicators, the application of two or more springs, which by
the difference in pressure above and below the piston, work conjointly, partly by
tension and partly by compression, as shown in Fig. 7.
Seventh. In duplex indicators, the arrangement of a separate spring for each
piston, so that each may work independently of the other.
Eighth. The arrangement of two pistons and two springs in duplex indicators
in combination with the link work shown in Figs. 8 and 9 for the production o
the combined diagram.
Ninth. In duplex indicators, the arrangement shown in Fig. 11, in which one o
the piston rods is caused to carry the card drum while the other piston rod carrie
the tracing pencil.

page_text: Tentb. In duplex indicators, the use of two diaphragm or Schaffer springs,
substantially as and for the purpose described.
Eleventh. In duplex indicators, the use of two curved tubular or Bourdon springs,
substantially as and for the purpose described.
In witness whereof, I, the said Arnold Budenberg, have hereunto set my
hand and seal, this Tenth day of April, in the year of our Lord One
thousand eight hundred and eighty two.
ARNOLD BUDENBERG. (LS.)