Improvements in or relating to the Indication of Temperatures.
Year: 1895

page_text: Date of Application, 25th July, 1895
Complete Specification Left, 27th Apr., 1896-4ccepted, 25th July, 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Indication of Temperatures.
We, CHARLES EDWARD VERNON, of 471 Barking Road, Plaistow in the County
of Essex, Engineer, and ARTHUR Ross, of St. Clement's, Carshalton Road, Sutton,
in the County of Surrey, Gentleman, do hereby declare the nature of this invention
to be as follows:-
This invention relates to apparatus for indicating temperatures, its object being to
enable a person to obtain at a central station an indication of the temperature existing
at another station or at a number of other stations which are more or less distant from
him or from each other.
According to one mode of carrying this invention into practice we employ at each
distant station a therinometer adapted to indicate temperature by moving a hand or
index, and in proximity to the hand or index a series of electric contacts are provided
over which it passes in succession without actually touching them until caused to do
so in the manner hereinafter explained, in order that the sensitiveness of the instru-
ment may not be impaired.
The hand or index is in circuit with a source of electric power, and has adjacent to
it an electro-magnet controlled by a push-button or the like at the central station.
At the central station there is a series of indicators like those in a hotel annunciator
with or without a bell each indicator of the series being connected to one contact in
the aforesaid series of distant-station contacts.
When the push-button at the central station is pressed the electro-magnet at the
distant-station is energised and pulls the band or index at the distant station into
close contact with that one of the contacts over which the temperature has placed it,
and so completes the battery circuit through the needle, through that contact, and
also through the corresponding division of the central station indicator, thus giving a
corresponding temperature-indication at the central station.
Instead of a series of indicators at the central station we may employ a galvano-
meter, and place different resistances in the leads carried to it from the different
contacts at the distant station so that different temperatures are indicted by different
degrees of deflection of the galvanometer needle, resulting from differences in the
current.
Or we may electrically connect each of the distant-station contacts separately with
the corresponding contact of a similar series provided at the central station, and
employ a spring-jack to electrically connect the hand or index of any distant-station
instrument with a battery. Therewith we use a central station switch to close circuit
to each central station-contact in succession and a central station bell the latter
ringing as soon as the switch adjustment at the central station (effected by hand)
corresponds with the index adjustment at the distant station (effected by the
thermometer) and is thereby enabled to complete the circuit.
From the foregoing it will be seen that a number of distant stations can have the
contacts of their thermometers connected similarly to the same central station
indicators or the like a push button and tilting hand or index being provided for each
distant station, for only one distant station is in circuit at a time.
For operating the hand or index of the thermometer we preferably employ a
compound bar are or spring of different metals such as is employed in the well-known
compensation balance, but we may use any other thermometer capable of closing
electric circuits in turn for the purpose specified. Where the compound bar or a
compound are or spring is used we preferably support one end of it on an easily-
adjustable block so that by moving the block a suitable initial adjustment of the bar

page_text: may be easily effected. And we prefer also to employ a spring whose tension can be
readily regulated, to vary the sensibility of the instrument by acting on the bar are or
spring or on the index.
At either end of the series of distant-station contacts we may provide special
contacts to control a special maximum and minimum alarm indicator at the central
station.
Should the index of the distant station thermometer close two circuits simul-
taneously to the central station indicators, two of those indicators will be operated and
the temperature must be considered as lying between the two indications.
Dated this 25th day of July 1895.
BOULT & WADE,
Agents for the Applicants.
Improvements in or relating to the Indication of Temperatures.
We, CHARLES EDWARD VERNON of 471 Barking Road, Plaistow, in the County
of Essex, Engineer, and ARTHUR Ross of St. Clement's, Carshalton Road, Sutton,
in the County of Surrey, Gentleman, do hereby declare the nature of this invention,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to apparatus for indicating temperatures, its object being to
enable a person to obtain at a central station an indication of the temperature existing
at another station or at a number of other stations which are more or less distant from
him or from each other.
In the accompanying drawings
Figure 1 illustrates diagrammatically an installation of temperature-indicating
apparatus according to this invention ;
Figures 2 and 3 are views at right angles to each other of a thermometric and
electro-magnetic circuit-closing device forming part of this invention, and of the
system shown in Figure 1 ;
Figure 4 is a plan view of a detail of Figures 1 and 2 ; and
Figures 5 and 6 are diagrams of installations differing slightly from those shown in
Figure 1. as is hereinafter explained.
Like letters indicate like parts throughout the drawings.
With reference first to Figure 1 an electric indicating-device A constitute by a
series of electric annunciators A¹
A 6 with the usual bell, if desired, is
provided at the central station at which the temperatures are to be read; each
annunciator operates to indicate a given temperature and two adjacent annunciators
operated simultaneously indicate a temperature intermediate between that which
either one would indicate singly, so that the series of annunciators indicates a series
of eleven temperatures. At each distant station the temperature of which is to be
taken (there being four such stations in the present example) is a thermometric and
electro-magnetic device B, the several devices being distinguished by a suffix and
lettered Ba Bb Bc Bd, each being adapted to indicate temperatures by moving an
In proximity to each hand or index is an electric contact D comprising
parts D'
D6 insulated from each other and allotted respectively to the
several annunciators A'... A 6 of the indicating-device A; over these parts
when the temperature alters, the index passes without actually touching them until
caused to do so in the manner hereinafter explained, in order that none of the indexes (
may make connection with its contact D except at such times as it is caused to do so
by electro-magnetic devices as hereinafter explained; as only one of the electro
magnetic devices is operated at a time no two of the indexes ( will close circuits
simultaneously so that confusion of indications from different distant stations is
index C.

page_text: avoided and the use of a single common main or series of mains instead of separate
mains or series of mains appropriated to each individual distant station. is rendered
practicable. Moreover the arrangement of index and contact so that they normally
do not touch prevents the sensitiveness of the instrument from being impaired by
unnecessary friction. E is a source of electric energy for the installation. a battery
being indicated; F is an electro-magnet adjacent to the hand or index C in each
device Ba.....
Bd, each hand and each electro-magnet being in two battery circuits
hereinafter described, which however are normally interrupted. G is a series of push-
button or other switches Ga Gb Gc Gd at the central station; they connect it with
the instruments Ba Bb Be Bd respectively. The several electro-magnets F are
"in parallel" with the battery E and controllable individually by the switches in the
series G; any of the indexes C caused by its electro-magnet to touch one of the
parts D¹.
D6 puts that part and the corresponding annunciator of the series A
in parallel with that electro-magnet. The circuits are arranged as follows:-H is a
lead from the battery E to all the annunciators in the series A; 1, 2, 3, 4, 5 and 6
are leads connecting the annunciators A' ... A 6 respectively with the_corre-
spondingly-numbered parts D'. . . . . D 6 of the contacts D of all the devices Ba, Bb,
Bc, Bd, there being normally an interruption of circuit at those parts until the gap
between them and the adjacent index is bridged as hereinafter explained. J and Ja
Jb, Jc, Jd, are leads connecting the lead H in parallel with the electro-magnets F.
Ka, Kh, Ke, Kd, are leads which respectively connect the electro-magnets F with
the indexes C by way of their supports and pivots and also with the switches Ga, Gb,
Gc, Gd, which in turn are connected by the lead L to the battery E, there being
normally a gap at the switches G to interrupt the continuity of the leads K₁, Kb,
Ke Kd.
Let it be desired, for instance, to ascertain at the central station the temperature
prevailing at the station at which the device Bb is situated; the push-button Gb is
pressed and completes the circuit E, L, Gb, Kb, F, Jb, J, H, E, energising the
electro-magnet F of the device Bb which then moves the index C of that instrument
into actual contact with that one of the contact parts D1.. D 6 over which the
thermometric action of the device has placed it, thus completing a shunt from the
previously-completed battery circuit E, L, Gb, Kb, F, Jb, J, H, E, through
the index C and also through the corresponding division of the central-station
indicator A, thereby giving a corresponding temperature-indication at the central
station. For example if the index C made contact with the part D 2 of the contact D
in the device Bb, the circuit completed by closure of the gap between the parts C
and D 2 would be from the battery E by way of leads L, Gb, Kb, to and through the
shunt C, D 2, 2, to the annunciator A 2 and thence by way of the lead H back to the
battery E.
At the end of the series of parts D 1
D 6 of each distant-station contact,
contacts can be provided to control by current transmitted through a special wire, a
naximum and minimum alarm indicator at the central station. The contact
parts D1 and D 6 might be appropriated to this purpose if not otherwise employed.
When the index of the distant-station thermometer closes in any one instrument
such as Ba two circuits simultaneously to the central-station annunciators, two of
those annunciators will be operated and the temperature must be considered as lying
between the two indications.
Thus it becomes possible with a given number of annunciators to obtain not only a
reading from each annunciator, but also a reading from each pair whereby the
number of annunciators and wires required for a given number of readings is reduced
to nearly one half. The numerals 16 to 26 on the device A in the present example
show that it is adapted to give eleven indications by means of six annunciators.
With reference now to Figures 23 and 4 which show one of the thermometric and
electro-magnetic circuit-closing devices such as Bb in detail, it will he seen that its
index (which is slightly flexible is supported by pivots on a plate M its lower end
being linked to a compound segment N of different metals, such for example as is
employed in the well known compensation balance. One end N1 of the segment is

page_text: supported on a block C which is readily adjustable by a screw P to effect a suitable
initial adjustment of the index for the purpose of calibration; the other end N2 is
linked by the link N3 to the lower end of the index, so that when the curvature of
the segment N alters with changes of temperature the index C is so moved that its
upper end C1, in proximity to but normally not touching the contact D and between
the latter and the armature F1 of the electro-magnet F, moves across the
sections D1.... D6 of the former, which are insulated from each other. The
armature F1 is supported by springs F2 so as normally to be clear of the poles F 3
and the index C. When the electro-magnet F becomes energised in the manner
herein before described it draws the armature F 1 towards the poles F 3 and thereby
bends the index C into contact with one or other of a pair of the parts
DI ... D6
of the contact D, to bridge the gap previously existing between them and the index.
The index then becomes part of the circuit E, L, Gb, Kb, C, D 2, 2, A2, H, E, for
example of Figure 1, the path of the current in the instrument itself (when the index
closes the circuit) being indicated by chain lines in Figure 2. Preferably the upper
end C1 of the index C carries a small bevelled projection C2 (seen in plan in
Figure 4) and the several sections D1.... D 6 of the contacts D are bevelled or
otherwise formed so that gaps exist between them (see Figure 2) into which the
projection C2 can enter. If the upper end of the index C does not happen to be
opposite the middle of any one section of the contact when attracted by the electro-
magnet the bevelled projection enters one of the gaps and ensures the establishment
of good electrical contact with the two sections at each side of the gap. The face of
the contact D opposed to the index is preferably flattened to ensure good electrical
contact between it and the index whenever they come together.
There is an adjustable pin-and-slot connection between the link N 3 and the smaller
arm of the index C to enable the ratio of the movement of the index to that of the
segment N to be varied as desired. Small springs may be employed as is customary,
to prevent backlash in the mechanism of the thermometric indicator.
Instead of a series of indicators at the central station a galvanometer may be used,
having different resistances in the leads taken from the different contacts D at the
distant stations to a single main S so that for each temperature a different current
goes to the central station, and the different currents are indicated by different
degrees of deflection of the galvanometer needle.
Such an arrangement is indicated diagrammatically in Figure 5 wherein A is the
galvanometer and R are resistances inserted in the leads, no two resistances being of
like electrical value; S is the single main to which all the resistances are connected.
Otherwise the system illustrated in Figure 4 is the same as that shown in Figure 1.
As a further alternative each of the distant-station contact parts D1...
D6 can
separately be electrically connected with the corresponding parts of a similar series
provided at the central station, a switch of any convenient or well known type being
used to complete the electrical connection of any one of the distant station instru-
ments at a time with the battery. Therewith is used a central-station switch to close
circuit to each central station-contact in succession and a central-station bell, the
latter ringing as soon as the switch adjustment at the central station (effected by
hand) corresponds with the index adjustment at the distant station (effected by the
thermometer) and is thereby enabled to complete the circuit. For the bell some other
indicator may be substituted if desired.
This further alternative is indicated diagrammatically in Figure 6 wherein A is the
central station switch, provided with a pivotted arın A7 adapted to make_contact
with each of the sections A 1...... A 6 in turn, and connected by the lead H which
in this instance includes a bell H 1 to the battery E, and a spring-jack H 2, by which
the circuit in the lead H may be completed or interrupted. The sections A 1
are each connected as shown to the corresponding parts of the contacts D of the
instrument Ba, by leads 1, 2, 3, 4, 5, 6, and the system is otherwise similar to that
which is illustrated in Figure 1.
A 6
With the instrument Ba in circuit and the spring-jack H2 inserted the bell H1
rings as soon as the arm A7 makes contact with that one of the parts Al .... A6

page_text: corresponding to the particular section of the contact D with which the index O
engages.
Instead of such a device as Bb for instance, any thermometric device capable of
controlling electric circuits may be employed for a like purpose, according to this
invention which is not limited to the particular arrangements and combinations of
parts hereinbefore described by way of example.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In the electrical indication of temperatures, obtaining at one station an indi-
cation of the temperature from any part of the scale of a thermometric device at
another station.
2. In apparatus for indicating temperatures the combination with a central
indicating-device of a thermometric appliance such as B, and means substantially as
described whereby the indications of the appliance B can be transmitted to and
repeated at the central indicating-device.
a
3. In apparatus for indicating temperatures the combination with an indicating-
device such as A, of a thermometric appliance such as B having a moving index C,
divided contact such as D normally clear of the index, leads from A to B and electro-
magnetic apparatus to cause a circuit through the index (and contact D to be
completed when desired, substantially as described.
4. In apparatus for indicating temperatures the combination with a galvano neter A
and resistances R, of a thermometric and circuit-completing device such as B to
control the galvanometer, substantially as described.
5. In apparatus such as described for indicating temperatures indicating devices
arranged to be used both singly and in pairs to reduce the number of parts required
for a given number of indications substantially as described.
6. In apparatus for indicating temperatures a thermometric and electro-magnetic
circuit-closing device such as B wherein mechanical contact of the circuit-closing
parts does not occur whilst the device, electrically, is idle.
7. In apparatus for indicating temperatures an instrument such as B wherein the
index C and the parts of the contact D are so constructed and arranged relatively to
each other that the index can complete single or duplex circuits substantially as and
for the purpose described.
8. In apparatus for indicating temperatures the combination with an index such
as C of a divided contact such as D the adjacent sections of which have gaps between
them substantially as and for the purpose described.
9. In apparatus for indicating temperatures the combination with an indicating-
device such as A of a thermometric and circuit-closing device such as B, electrically
connected and operating substantially as and for the purpose described with reference
to Figure 6 of the accompanying drawings.
10. The combination and arrangement of parts constituting a complete apparatus
for indicating temperatures substantially as hereinbefore described and illustrated in
Figure 1 or Figure 5 of the accompanying drawings.
11. The combination and arrangement of parts constituting a complete thermo-
metric and electro-magnetic circuit-closing device substantially as hereinbefore
described and illustrated in Figures 2, 3 and 4 of the accompanying drawings.
Dated this 24th day of Anzil 1896
CHARLES EDWARD VERNON.
ARTHUR ROSS.
Boult & Wade,
Agents for the Applicants.
CHARLES EDWARD VERNON.
ARTHUR ROSS.
Boult & Wade,
Agents for the Applicants.