IMPROVEMENTS IN INSTRUMENTS OR APPARATUS FOR INDICATING EXCESSIVE VARIATIONS OF TEMPERATURE IN BUILDINGS, OVENS, VATS, HOT- HOUSES, AND OTHER PLACES " SP
Year: 1882

page_text: LETTERS PATENT to Walter Thomas Goolden of Bayswater, and Charles
Frederick Casella of Holborn, both in the County of Middlesex for an
Invention of "IMPROVEMENTS IN INSTRUMENTS OR APPARATUS FOR INDICATING
EXCESSIVE VARIATIONS OF TEMPERATURE IN BUILDINGS, OVENS, VATS, HOT-
HOUSES, AND OTHER PLACES
"
PROVISIONAL SPECIFICATION left by the said Walter Thomas Goolden
and Charles Frederick Casella at the Office of the Commissioners of Patents
on the 27th October 1882.
WALTER THOMAS GOOLDEN of Bayswater, and CHARLES FREDERICK CASELLA
of Holborn, both in the County of Middlesex, "IMPROVEMENTS IN INSTRUMENTS
OR APPARATUS FOR INDICATING EXCESSIVE VARIATIONS OF TEMPERATURE IN
BUILDINGS, OVENS, VATS, HOTHOUSES AND OTHER PLACES."
Our Invention relates to instruments for indicating when the limits between
which it is desired to maintain the temperature in a building, drying oven, hot
house, conservatory, or other place, has been attained or exceeded, wherein a Six's
thermometer is combined with an electrical alarm whose circuit is normally open
and is closed by the indices in the thermometer tubes coming in contact with the
mercury.
We are aware that it has been before proposed to construct instruments of this
description wherein indices were employed for giving an audible signal when the
temperature surpassed predetermined limits. In such instruments however the
limits were arbitrary as the position of the indices could not be varied, and to
admit of the combination with the thermometer of the devices for operating the
alarm, it was necessary to sacrifice to some extent the efficiency of the thermo-
meter. The object of our improvements is to obviate these objections and to
provide an instrument whose indices shall be capable of ready adjustment to suit
any variation that it may be desired to make in the limits of temperature.

page_text: According to our Invention the indices are mounted on independent wires which
are loosely connected to fixed wires sealed in the bulbs and in electrical connection
with the alarm; the fixed wires may extend a short distance into the tubes of the
thermometer, or terminate within the bulbs. The connection between the wires
may be made by providing one set of the wires with eyes or a sleeve through
which the other wires pass freely, or the fixed wires may have links through one
or more of which the index wires may pass. In any case the connection will be
such that the indexes may be readily moved up and down within the tubes by
means of a magnet as usual in order that they may be set to indicate when the
maximum or minimum temperature to which the instrument is set to work, has
been exceeded, at which times the mercury coming in contact with one or other of
the indices, closes the circuit and operates the alarm.
If desired a visible as well as an audible signal may be given by placing a needle
working over a dial in the circuit, said needle being deflected in one or other
direction, according as the temperature has surpassed the limits, and we may
combine with the instrument a band moved by clockwork mechanism on which a
record may be made of the exact time at which the temperature was allowed to
rise or fall.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Walter Thomas Goolden and Charles Frederick Casella in the
Great Seal Patent Office on the 27th April 1883.
WALTER THOMAS GOOLDEN of Bayswater, and CHARLES FREDERICK CASELLA
of Holborn, both in the County of Middlesex "IMPROVEMENTS IN INSTRUMENTS
OR APPARATUS FOR INDICATING EXCESSIVE VARIATIONS OF TEMPERATURE IN
BUILDINGS, OVENS, VATS, HOTHOUSES, AND OTHER PLACES."
Our Invention relates to instruments for indicating when the limits between
which it is desired to maintain the temperature in a building, drying oven,
hothouse, or other place, have been reached. We are aware that it has before
been proposed to place a thermometer in the circuit of an electrical alarm, so
that the circuit which is normally open shall be closed by the mercury coming
in contact with a terminal wire fixed in the thormometer tube when the
temperature reaches the limit of the predetermined range. In such instruments
however such limit has hitherto been arbitrary as the terminal portion of the wire
when once sealed into the thermometer tube, admitted of no variation of position.
The object of our Invention is to provide an instrument of this description whoso
contact terminal or terminals shall be capable of ready adjustment to suit any
variation that it may be desired to make in the limits of the range of temperature,
without in any way impairing the accuracy of the instrument.
•
According to our Invention we provide any thermometer containing mercury
with an adjustable terminal wire or index, being an independent wire loosely
connected to and capable of sliding on a fixed wire sealed through the glass and
projecting into a part of the tube or a bulb attached thereto not occupied by the
mercury. The fixed wire extends a sufficient distance to afford the requisite range
of motion for the adjustable terminal, and the connection between the fixed and
movable wire may be made by providing the one with eyes, links, or a sleeve
through which the other would pass freely, the connection being such that the
terminal may be readily moved up and down within the thermometer tube whilst
remaining in electrical connection with the fixed wire. If only a maximum limit
is required to be indicated the movable terminal would be situated within a bulb
or enlargement of the bore at the upper end of an ordinary mercurial thermometer,
but if both maximum and minimum limits are required to be indicated, then a
Sixe's thermometer or any modification thereof must be used and in that case there ⚫
would be a movable terminal in one or both of the limbs of the instrument,
according as it is required to vary one or both limits of the range of temperature.
The annexed drawing represents a Sixe's thermometer provided with our
improvement which is in this case applied to both limbs. a a are the limbs, and
bb the bulbs which are elongated to permit of the adjustability of the terminals.
c is a platinum wire sealed into the bend of the tube a and in electrical contact
with the mercury therein, this wire being united to the binding screw C to which
one pole of the battery is connected, all as usual in alarms; d d are two platinum
wires scaled through the ends of the two bulbs b and passing centrally down the
same to about their point of junction with the limbs a, the outer ends of these two
wires being united with the binding posts D D which are both connected to the
other pole of the battery. ee, are the adjustable terminals or indices, being
platinum wires connected loosely to the wires d so as to be capable of being moved
up and down to any desired points in the limbs a whilst remaining in electrical
contact with the wires d. The connection between d and e is preferably double,
and consists first of a loop d' formed on the end of the wire d and of one or two

page_text: links connected thereto, through one of which links the wire 6 passes, and
secondly a ring e' running on the wire d and connected by one or two links c³ with
the end of the movable wire e. (see also detached view drawn to an enlarged
scale) The loop d' forms a stop to limit the motion of the wire e. f is a small
sterl pin, to an eye in the end of which the. wire e is connected to enable the latter
to be moved by the attraction of a magnet for the pin f, in the usual way of setting
the indices of an ordinary Sixe's thermometer when unconnected with any
electrical apparatus. Both wires e are similarly provided.
In the circuit of each of the branch wires attached to the binding posts D, an
electric bell is placed, the bells being of different pitch to indicate which branch of
the circuit is closed. Or instead of, or in addition to bells, electric indicators of
any suitable kind may be used. This alarm may be located at any convenient
distance from the thermometer.
Having described the nature of our Invention and the manner of performing the
same, we declare that what we claim as our Invention to be protected by the
hereinbefore in part recited Letters Patent is.
In a thermometer in which mercury is employed, the combination with a fixed
wire a sealed into the glass beyond the reach-of-the mercury, of-a-movable.terminal
wire or index e in electrical connection with the fixed wire and adjustable in the
thermometer tube, substantially as shown and described, for the purpose of closing
an electrical circuit in the manner specified.
In Witness whereof we the said Walter Thomas Goolden and Charles
Frederick Casella have hereunto set our hands and seals this twenty sixth
Jan A.-il A 1000
WALTER THOMAS GOOLDEN (L.S.). 2
CHARLES F. CASELLA.
(L.S.)