Improvements in Electrical Circuit Closing Thermometers.
Year: 1896

page_text: Date of Application, 8th June, 1896
Complete Specification Left, 27th Feb., 1897-Accepted, 3rd Apr., 1897
PROVISIONAL SPECIFICATION.
Improvements in Electrical Circuit Closing Thermometers.
I, ALEXANDER LURASCHI of 15, Cross Street, Hatton Garden, London, E.C.
Chemical and Experimental Glass Blower, do hereby declare the nature of this
invention to be as follows:-
My invention relates to an improved electrical circuit closing thermometer and it
has for its object to provide a closed thermometer with an adjustable terminal
capable of being set so that the closing of the circuit will ensue upon the attainment
of any given degree of temperature within the range of the instrument.
The invention relates particularly to the means of ensuring permanent electrical
contact between the movable and fixed parts of the conductor within the bore of
the tube and to the mode-of forming the movable terminal and ensuring the fixity
of its position after adjustment.
The movable terminal is formed of a length of very fine platinum wire passed
through a casing formed by a short tube of glass enclosing a piece of steel wire and
fused at both ends about the platinum wire so as to hermetically seal up the steel
wire within it, the ends of the glass tube being provided with small knobs of glass
to act as guides for the terminal in its motion through the bore of the thermometer
tube. The end of the platinum wire projects from the lower knob sufficiently to
make contact with the mercury column and a hair is tied about the glass tube to
act as a spring which by contact with the sides of the bore will retain the
terminal in the position at which it is set. The platinum wire above the glass
casing is of a length to suit the range of adjustment required and it makes contact
with the external conductor by sliding through a fine hole drilled transversely
through a platinum wire which passes across the bore and is sealed into the stein of
the thermometer, the adjustment being effected by means of a magnet acting
through the stem on the steel needle carried by the terminal.
Dated this 8th day of..June 1896.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Electrical Circuit Closing Thermometers.
I, ALEXANDER LURASCHI, of 15 Cross Street, Hatton Garden, London, E.C.,
Chemical and Experimental Glass Blower, do hereby declare the nature of this
invention, and in what manner the same is to be performed, to he particularly
described and ascertained in and by the following statement :-
My invention relates to an improved electrical circuit-closing thermometer, and
it has for its object to provide a closed thermometer with an adjustable terminal
capable of being set so that the closing of the circuit will ensue upon the attainment
of any given degree of temperature within the range of the instrument.

page_text: 3. In electrical circuit-closing thermometers, the combination of an adjustable
movable terminal completely enclosed within the thermometer tube, a short glass
tube through which the movable terminal is passed and which is sealed at each end
to such terminal, a steel needle within such glass tube, a perforated cross wire
through which the movable terminal freely passes and with which it makes contact,
such cross wire being fused into the thermometer tube and having one end
extending outside the tube to connect with an external conductor, and a fixed
terminal always in contact with the mercury, substantially as herein set forth.
Dated this 27th day of February 1897.
HARRIS & MILLS,
23 Southampton Buildings, London, W.C., Agents.