Improvements in and relating to Pyrometers or Thermometers.
Year: 1890

page_text: Date of Application, 4th July, 1890
Complete Specification Left, 2nd Apr., 1891-Accepted, 16th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in and relating to Pyrometers or Thermometers.
I, JAMES MURRIE, of 9 Granville Street, West, Glasgow, Lanarkshire,
Engineer, do hereby declare the nature of my invention to be as follows:-
This invention has reference to various special improvements in and connected
with that class of pyrometers or thermometers in which the heat to be indicated or
registered is imparted to a liquid at one end of a close tube, which by its expansion
and pressure within the tube is made to act within a Bourdon or other coil tube, or
it might be discs, so as to expand these by the pressure of the fluid within, at the
other end of the tube, and by gearing give motion to an index or pointer to register
the temperature of heat by the pressure within on a divided or graduated index
disc; which improvements will make this class of pyrometers or thermometers more
durable, efficient, and accurate in their action for the various purposes to which
they may be applied, than as heretofore constructed, and make them specially
applicable for the indicating of high temperatures.
The nature and novelty of the improvements consist all as follows:-First, in
making the tubes of these instruments (which act to indicate by the expansion and
pressure of the enclosed liquids or fluids and therefore require to sustain high heat
and pressure) of solid drawn steel, and with solid welded plugged ends, where they
have to be heated to expand the liquid or fluid within, and which may be termed
the heating or heat tube; and further in making those heat tubes, which require to
be used horizontally whether straight or with a spiral on the end nearest the
indicator to indicate the temperature within the chambers or vessels, with a knee
downwards at this outer end, and in coupling or jointing them laterally by a knee
coupling to the lower hollow box end of the tube coil of the index gauge, below
the level of the heat tube, so as to ensure that only the water, mercury, or other
liquid used shall act in the pressure gauge tube without gas or vapour, which for
accurate action must be all generated and retained at the hot end, so as to act by
its pressure on the liquid. Or the tube might be kneed downwards or upwards
and coupled by a straight coupling direct to the bored end of the hollow bush or
block part to which the neck of the spring coil of gauge is jointed. Or otherwise,
the straight outer end of the tube may be directly coupled to the hollow bush or
block at the centre or upper part of it, continued up from the neck part behind for
that purpose.
Another improvement consists in giving a slight knee downwards to the straight
solid drawn heat tube, keeping the outer part in line with the inner heating end, so
as to further ensure the gases or vapour being only enclosed within the close
heating end. A further improvement consists in fitting at the upper straight part
of the solid drawn heat tube a straight bar concentrically within it to contract the
area and require less mercury in this part of the tube and allow it a greater amount
of longitudinal motion along this contracted annular part between the bar and the
heat tube by the expansion of the liquid and vapour which may be water within its
close heated énd, to actuate the mercury.
By another improvement suitable for vertical arrangements of these solid drawn
heat tubes, I knee or twist the close heating end upwards and back parallel to the
nain stem of the tube, or in a coil up round this stem (which is inserted into the
chamber or vessel of which the heat is required to be taken and indicated) for
he pressure vapour to be generated within the close end. And I by a further
mprovement fit round the upper outer end of the tube an outer tube, close at the
ower end and open at the top, as a jacket to surround this tube, with air to main-
ain the temperature of this outer part of the tube as uniform as possible. By

page_text: another improvement, a hollow ball would be formed near the outer end of the solid
drawn heat tube, having the upper end of the tube directly connected to the lower
central part of the ball, while the lower end of the tube leading from the close
spring coil or indicator would project down as a nozzle with its end opening into
near the centre of the ball. In this instrument mercury would be filled into the
lower heat part of the tube up to near the centre of the ball, some little distance
from the open end of the nozzle of the upper tube of the indicator which would
be completely filled with water as well as the ball over the mercury; or the ball
might be made in two parts or of two hollow cups with a close jointed elastic
diaphragm between them having the mercury only within the heat tube on the
lower side of the diaphragm and the water on the higher side, in which case the
nozzle in the water division would not be required. These arrangements would
give great surface pressure of the mercury on the water and require less length of
tubes for the range of motion and pressure necessary for high temperatures, and
also prevent the possibility of the water getting down into the heat tube, or the
mercury up into the upper water tube or spring coil of gauge, and be very suitable
for taking high temperatures and giving increased motion of the indicator coil and
index.
By another arrangement in which mercury only is used in the heat tube, and in
the elastic tube of the indicator, also suitable for high temperatures, this latter
indicating coil tube is made of solid drawn steel directly connected at its free end
to the multiplying toothed mechanism of the index or pointer of the indicator.
A further improvement consists in fitting an outer metal close or open ended
sheet metal shield or case round the heating tube, either round the whole of the
tube or at the upper or lower end where it is to be heated. A further improvement
consists in fitting to these instruments make and break clectric contacts to be
connected by wires to any local battery and alarm mechanism in the circuit and in
the plane of the indicator pointer inside, but preferably capable of being shifted
from the outside round the case to such positions of range of temperature of the
pointer desired, so that when the pointer falls to or below a certain temperature, or
rises to or beyond a certain temperature of range desirable, it will make contact
and complete the electric circuit and ring a bell or make an alarm in either case
to draw the attention of the attendant to the increased or diminished temperature
of the place or material to which the pyrometer is applied.
Dated the 3rd day of July 1890
W. R. M. THOMSON & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Pyrometers or Thermometers.
I, JAMES MURRIE, of 9 Granville Street, West, Glasgow, Lanarkshire,
Engineer, do hereby declare the nature of my invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement in writing, reference being had to the accompanying
drawings and to the letters and figures marked thereon, that is to say :-
This invention has reference to various special improvements in and connected
with that class of pyrometers or thermometers in which the heat to be indicated or
registered is imparted to a liquid at one end of a close tube, which by its expansion
and pressure within the tube is made to act within a Bourdon or other coil tube, or it
might be discs, so as to expand these by the pressure of the gas or fluid within at the
other end of the tube, and by gearing give motion to an index or pointer to register
the temperature of heat by the pressure within on a divided or graduated index
disc;
which improvements will make this class of pyrometers or thermometers
more durable, efficient, and accurate in their action for the various purposes to

page_text: which they may be applied, than as heretofore constructed, and make them specially
applicable for the indicating of high temperatures.
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereunto
appended two explanatory sheets of drawings, in which the same reference letters
are used as far as possible to indicate like parts in all the figures where shown. In
these drawings the heat tubes a, a, are all shown as broken away at a*, but they
might be made of any suitable length as generally 4 or 5 feet long.
Figure 1 on Sheet 1 is an elevation partly in section of one construction of
pyrometer in accordance with and illustrative of my improvements as applied to
horizontal pyrometers.
Referring to the drawings. The improvements consist all as follows, first, in
making the tubes a a¹ of these instruments (which act to indicate by the expansion
and pressure of the enclosed liquids or fluids and therefore require to sustain high
heat and pressure) of solid drawn steel, and with solid welded or plugged ends at a¹
where they have to be heated to expand the liquid or fluid within, and which
may be termed the heating or heat tube; and further as shown in Figure 1
in making those heat tubes a which require to be used horizontally whether
straight or with a spiral coil a on the end nearest the indicator as shown in
Figure 2 A to indicate the temperature within the furnace chambers or vessels
where the end a' is inserted for that purpose with an angle or knee downwards
towards the indicator at this outer end a¹ a¹ to ensure that the mercury or other
fluid employed shall fill the main horizontal part of the tube a a¹; and in coupling
or jointing it direct laterally by a knee coupling piece a² or it might be a preferably
hexagonal in outer shape by a screw and sharp angled annular end joint a" and by
a similar screw joint a³ to the screw coupling A³ of the neck piece A² of the tube
coil A¹ of the index gauge A but preferably with a copper washer all below the
level of the heat tube a, a', so as to ensure that only the water, mercury, or other
liquid used shall act in the pressure gauge tube A¹ without gas or vapour, which for
accurate action must be all generated and retained at the hot end a¹ so as to act by
its pressure on the liquid in the lower part of the tube a intermediate joint pieces,
and tube and gauge A. The mechanism of the acting tube A' within the gauge
may be of any of the usual constructions to turn the usual wheel spindle and
indicating pointer P, over the divided index showing through the glass in the
gauge A, to indicate the temperature by the pressure within the tube A. Or as
shown in the sectional elevation Figure 1 A, instead of using the knee piece a² the
gauge end of the tube a a' may be kneed as shown at all and screwed and jointed
direct to the coupling A³ of the gauge. Or as shown in the elevation Figure 2,
the gauge end of the tube a might be kneed downwards and upwards in a siphon
form as shown at all and screw jointed direct to the bored screwed end of the
coupling A3 of the hollow bush or block part A2 to which the neck of the spring
coil A' of gauge A is jointed. Or otherwise as shown in the elevation Figure 3, the
straight outer end of the tube a may be directly screw coupled to the coupling A³
of the hollow bush or neck block A2 of the tube A' of the gauge A coupled direct
in line, or continued up from the neck part at a behind the gauge case A¹ for that
purpose as shown in Figure 2 A. And as shown in Figure 3 an outer tube case b
may be screwed to the outer end of the coupling piece A³ leaving an annular air
space between the tube a, and the outer case b, which is open at the inner
end for the purpose of keeping this outer part of the tube a from being acted on
by the heat applied to its inner end a¹. And although the index face of the
gauge A is shown in these figures as turned longitudinally to the side of the gauge
tube a, a', it might be turned edgeways to it, and so show the index and pointer on
the end of the gauge tube, instead of the side as shown in these three figures.
Figure 4 shows a sectional elevation of another modification of these horizontal
arrangements of pyrometers, in which a hollow cylindrical or ball shaped diaphragm
case B B is formed in two parts jointed and screwed together at the centre, with
a diaphragm B2 secured between them, leaving a space B" on the one side of the

page_text: hollow box next the gauge for water, glycerine, or other equivalent to act within
the coiled tube A', of the gauge, while mercury or other liquid might be used in
the heat tube a, a', and in the division B on the other side of the diaphragm B²
The one disc part B of this diaphragm chamber may be formed or screwed on
to the coupling A³ of the gauge, while the outer end a of the heat tube, would be
screw coupled at all to the outer disc part B B₁ of the diaphragm chamber; and
the diaphragm B2 might be made of good vulcanized rubber or of elastic steel plate,
annularly corrugated within the chamber of the disc.
A further improvement consists in fitting in the gauge end a a of the solid drawn
heat tube a¹ a long straight bar concentrically within it analogous to C in
Figures 8 and 9, to contract the area and allow an annular cylindrical space instead
of the small central hole through this bar shown in Figures 8 and 9, and require
less mercury in this part of the tube and allow it a greater amount of longitudinal
motion along this contracted annular part between the bar and the heat tube by the
expansion of the liquid and vapour which may be water within its close heated
end a¹ to actuate the mercury.
Another improvement consists in giving a slight knee downwards to the straight
solid drawn heat tube a a' of these horizontal arrangements that is to keep the
inner heating end a', a', higher than the outer end a so as to further ensure the
gases or vapour being only enclosed within the close heating end while the liquids
would be all in the outer gauge end of the tubes a¹.
By another improvement suitable for vertical arrangements of these solid drawn
heat tubes a, a', shown in sectional elevation in Figures 5 and 6, I knee the close
heating ends a¹ a' upwards and back parallel to the main stem a a of the tube, or as
shown in the sectional elevation Figure 7, I twist this heating end a' a' in a coil up
round this stem a (which is inserted into the chamber or vessel of which the heat
is required to be taken and indicated) for the pressure vapour to be generated
within the upper close end of the return part a', this arrangement being shown with
a diaphragm chamber B to B analogous to that shown in Figure 5. And I by a
further improvement shown in Figure 5 fit round the tube a an outer cased tube b
analogous to that shown in Figure 3, but screwed to a cap close at the lower end 12
and open at the top end 611 as a jacket to surround this tube a with air to maintain
the temperature of this outer part a of the tube as uniform as possible. In this
modification a diaphragm and chamber is shown, analogous to that shown in the
horizontal arrangement Figure 4, and lettered to correspond, to separate the liquid
acting in the tube from that acting within the coiled tube A' of the gauge A,
except that a nipple is projected down into the water or liquid within the
chamber on the outside of the diaphragm B². Figure 6 is equivalent to Figure 5
except that the diaphragm chamber B to B is dispensed with, and the upper end
of the tube a is screw jointed direct to the coupling A³ of the gauge, and the outer
casing tube is shown with openings 6" at the upper end. The arrows in all these
figures indicate the direction of the pressure within the gauges, and indicated on
the dial by the pointer P which gives a graduation proportional to the temperature
applied to the inner ends a¹ of their heat tubes a a'. In these Figures 5 to 7 water
or other liquid may be used to act in the turned up heat ends a in the space m¹
above the mercury m.
Referring to the Figures 8 to 14, on Sheet 2, these show sectional elevations of
vertical arrangements of pyrometers, analogous to those shown in Figures 5, 6
and 7 on Sheet 1, but with wide chambers or enlarged bulbs at all instead of the
turned up ends shown on Sheet 1, for the mercury acting through the tube a a¹;
and a wide chamber or bulb B3 as an equivalent for the chamber B B for con-
taining the water or other liquid above the mercury desired to act in the gauge
tube A' of the index A. Figure 8 shows a pyrometer to a small scale constructed
in accordance with one simple form of this arrangement, in which Figure 9 shows
the lower and upper vessels C', B³, in enlarged section. In this arrangement the
mercury is filled into the lower chamber or bulb C with or without water or other
liquid above it, while a long tube C fills up a great part of the upper tube a, a,

page_text: leaving the enlarged part C¹ of the vessel below. A small dip tube C" projects
down from the lower end of the tube C to near the bottom of the mercurial
chamber C¹ so that when this lower end is heated, the vapour may generate above
it at m¹ around the dip tube C", and force the mercury m up this tube C", to some
distance above its top end, as indicated at m" above which water or other liquid would
be filled in, to fill the upper vessel B³ and tubes of the indicator A above this. The
upper end of the outer tube a would be screw coupled at a direct to the coupling A³
of the indicator; and within the upper end of the tube a or the coupling A³, a plug
tube socket piece c¹ would be screwed, having a dip nozzle or tube c reaching well
down into the upper water vessel B³, analogous to the nipple shown in Figure 5.
When the mercury rose by pressure in the vessel B³ it would force the water or
other liquid in it up through this tube c, c', into the coupling A³ above, and to the
acting coiled tube A¹ of the indicator, and so act substantially as in Figure 5
without a diaphragm. Figures 10 and 11 show sectional elevations of the top
part a a of a pyrometer tube arranged substantially the same as those shown in
Figures 8 and 9, but having an indiarubber bag B2 fitted in the upper chamber B³
as an equivalent for the diaphragm B2 shown in some of the former figures secured
at its open top to the nipple or lower neck of the plug tube socket piece c' within
which and the bag B2 the water alone would be enclosed to act therein, and in the
coil expanding tube A' of the indicator. The bag is shown sustained in its
stretched form by the outer circumference of the nipple or tube c in Figure 10,
while in Figure 11 it is shown sustained by four or other number of bow wires c¹.
Referring to Figure 12 which is a sectional elevation of a pyrometer with an
enlarged bulb or vessel at its lower end a', a', and a very small hole up the centre
of the tube a right up to the coupling A³ of the indicator without a separate
chamber B3 or B, shown in some of the former figures, for a different fluid, and in
which water or other analogous, fluid would be used, filled into the lower bulb a¹
leaving space at m¹ for vapour at the upper part of the bulb, which when heated
would cause the vapour to ascend the small bored tube a and fill the coiled tube A',
of the indicator A and condense in these upper cold parts not subjected to heat,
the pressure of the condensed fluid acting in the coil to turn the pointer P of the
indicator. This arrangement would act with a coil tube at as shown in Figure 2 A.
Figure 13 shows a sectional elevation of an arrangement of heat tube a with fine
bore also, analogous to Figure 12, but having an enlarged chamber B³ at the upper
end of the tube a. In this case mercury would be used in the lower part of the
bulb a', a', and in the lower part of the bulb B³, and water or other analogous
liquid filled in above this or it might be air, in this upper bulb, and in the acting
coil tube A¹ of the indicator while a space would remain above at m' in the bulb a¹
for vapour of mercury, which would ascend the small bored tube a, and be
condensed therein and act on the mercury m¹¹ in the upper bulb B³. Figure 14
shows a sectional elevation of the heat tube a, a', analogous to the one described
in Figure 13, but having the heating bulb end a¹ for the mercury m turned up
analogous to those shown in Figures 5 and 6, Sheet 1, leaving the space m¹ in the
upper part of the bulb a', a', so that when heated the pressure of the vapour acts
on the surface of the mercury m in this bulb, and forces it up the small bored
tube a into the mercury m in the lower part of the bulb B3 and above this
mercury, air, or other fluid might be used to act within the coiled tube A¹ of the
indicator A; and when air or water is used above the mercury m², these interior
parts of the tubes may be coated with lead, tin, or other material to prevent
corrosion. A nipple e is shown as preferably formed in the upper part of the
chamber B³ dipping down into the space above the mercury m¹¹.
these arrange-
ments Figures 13 and 14, the coil as shown in Figure 2 A may be used instead of
the bulb B³, either with or without water filled into the indicator tube A' above the
mercury.
When mercury only is used in the heat tube a, a', and in the elastic acting
tube A of the indicator A suitable for indicating very high temperatures, as may

page_text: be the case in any of these pyrometers. Figures 1 to 3, 6 and 13 and 14, without
a diaphragm B2 or separating liquid vessel B2 or B3 at the indicator end a of the
heat tube; the acting coil tube A¹ by another improvement is made of solid drawn
steel directly connected at its free moving end to the multiplying toothed
mechanism of the index or pointer P, of the indicator as shown in Figure 1 A.
The arrangements with the diaphragms and bags B2 in the upper chambers and
parts of the heat tubes a, a', would give great surface pressure of the mercury on
the water and require less length of tubes for the range of motion and pressure
necessary for high temperatures, and also prevent the possibility of the water in
the coiled tube A of the indicator A getting down into the heat tube a a¹ or the
mercury up into the upper water tube or coil tube A' of gauge A', and be very
suitable for taking high temperatures and giving increased motion and power to the
indicator coil and index, as for making the index do some work, such as for giving
an alarm through electric contact mechanism. Any of these instruments may be
fitted with make and break electric contacts or terminals t t¹ as indicated in
Figure 3 to be connected by wires to any local battery and alarm mechanism in the
circuit and in the plane of the indicator pointer P inside, but preferably capable
of being shifted by a knob on each terminal t t¹, from the outside round the case to
such positions of range of temperature and pressure of the pointer desired, so that
when the pointer P falls to or below a certain temperature, or rises to or beyond a
certain temperature of range desirable, it will make contact with the said
terminals t, &, and complete the electric circuit and ring a bell or make an alarm,
in either case to draw the attention of the attendant to the increased or diminished
temperature of the place or material to which the pyrometer is applied.
Figure 15 shows a sectional elevation at the top part of the tube a, of an arrange-
ment of mercurial vessel B4 analogous to Figure 14, that is as to the lower heat
end a' a' of the tube a, but not shown in this figure, in which a close or solid
cylinder B is floated in the mercury, attached to an elastic diaphragm B2 on the
top of the vessel B, gripped between this and an outer top ring B6, connecting the
centre of this diaphragm by a stem or link D to the horizontal arm D' of a bell-
crank lever D', D2, fulcrumed at D" to a fixed stud D screwed to the closing
cover of the chamber B4. The vertical lever D² may also form the index pointer P
of this arrangement of gauge moved directly by the pressure within the vessel B*,
the quadrant P being divided to indicate degrees of temperature due to the
pressure generated by the heat applied to the lower bulb end a' a' of the tube a,
otherwise substantially as in the former modifications of diaphragm arrangements.
The horizontal arm D¹ would be loaded with a counterweight D³ to regulate the
initial movement of the float and pointer P and it might be made to bring the
diaphragm B² with its moving cylinder B and pointer P, always back to their
normal zero position due to the temperature and pressure of the instrument when
no heat was applied. This arrangement would be very powerful for giving
indications of alarm, and in this case would preferably have a pulling rod P2
attached to the lever D2 or pointer P to act and give an alarm mechanically or
through electric contact mechanism, when the temperature rose to or above the
temperature desired.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is.-
First. The construction, or arrangement and combination of the parts of pyro-
meters with the heat tubes a a¹ formed of solid drawn steel, and either arranged to
work horizontally or vertically, with mercury, or mercury and water, or other
liquids, separate or combined, and otherwise constructed, substantially as herein
described, in reference to and illustrated under the various applications in the
accompanying drawings.
Second. The constructing of pyrometers with heat tubes a a¹ of solid drawn steel,

page_text: and solid welded or plugged ends, substantially as and for the purposes herein
described, in reference to, and by way of application shown in the accompanying
drawings.
Third. The constructing of pyrometers with their heat tubes arranged horizontally
and having their heating end higher than the indicating end, and having the outer
end coupled to the indicator by a knee bush or bend, or kneed downwards and
upwards, or directly coupled at said outer end, to the hollow bush or neck block of
the gauge tube, substantially as and for the purposes herein described in reference
to and shown in the accompanying drawings.
Fourth. The constructing of pyrometers with a straight bar concentrically within
the heat tubes to contract the area in which the mercury works, substantially as
herein described in reference to and shown in the accompanying drawings.
Fifth. The constructing of pyrometers with solid drawn steel heat tubes,
arranged vertically and kneed or twisted backwards and upwards at their close
heating ends, substantially as herein described in reference to and shown in
Figures 5 to 7 and 14 of the accompanying drawings.
Sixth. The constructing of pyrometers with an enlarged chamber on the heat
tube near the indicator, either with or without an elastic diaphragm or bag,
substantially as and for the purposes herein described, in reference to and shown in
the accompanying drawings.
Seventh. The constructing of pyrometers with an open ended outer shield or
jacket tube round the heating tube, substantially as and for the purposes herein
described in reference to and by way of application shown in the accompanying
drawings.
Eighth. The constructing of pyrometers with their elastic acting coiled tubes
formed of solid drawn steel for the use of mercury in them, substantially as herein
described in reference to and by way of application shown in the accompanying
drawings.
Ninth. The constructing of pyrometers to give an alarm by make and break
electric contact connections to complete the circuit, or by a direct mechanical con-
nection, actuate a bell or alarm when the temperature rose above or fell below
predetermined points of temperature, substantially as herein described.
Dated the 1st April 1891.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.