Improvements in Thermometers.
Year: 1893

page_text: Date of Application, 15th July, 1893
Complete Specification Left, 14th Apr., 1894-Accepted, 19th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in Thermometers.
ALFRED ERNEST DEAN Meteorological Instrument Maker 73 Hatton Garden
London do hereby declare the nature of this invention to be as follows:-
My invention has reference to a class of thermometers which are constructed
with a steel (or other material) detached index, for the purpose of registering the
maximums & minimums of heat & cold.
These indices are constructed to float on the surface of the mercury in the
thermometer or are suspended above the mercury if desired, & by being brought
into contact with the mercury are rendered operative.
In my improved thermometer I isolate or remove from the indicating portion of
the thermometer the beforementioned indices. This I do in the following manner:
I construct my thermometer with the ordinary bulb or reservoir & the capillary
or indicating portion of the thermometer & I fill my thermometer with the usual
thermometrical fluids. Beyond these indicating or reading portions of the ther-
mometer I apply my improved method of construction, which consists of a small
tube or tubes placed at the ends of the indicating portions or stem of the
thermometer. These tubes I place in the interior of the thermometer in such a
manner & of such proportions as to allow me to pass the index or indices out of the
bore of the thermometer when desired.
To attain this I construct at the end or ends of the bore of my thermometer a
cavity or enlargement of suitable dimensions, which may be immediately touching
the reservoir or may be a little removed from it, & in this cavity or enlargement I
place my improved tubes which I place in such a manner that the ends of the
improved tubes do not touch the ends of the bore of the thermometer & the other
ends of these improved tubes I fix in the most convenient manner.
These improved tubes placed as described enable me to pass the index or indices
of the thermometer out of the bore into these tubes whilst travelling & the enlarged
portion or cavity beforementioned receives the disconnected portions of mercury
which have separated whilst travelling from the main body.
These disconnected portions are not in contact with the index or indices which
were previously passed into the improved tubes, & the thermometer on arriving at
its destination is placed in a vertical position & the disconnected globules of mercury
fall by gravity out of the enlarged portion or cavity & join the main body or assume
their proper position & in this manner the operative elements of the thermometer
are in no way engaged one with another & at a suitable period the index or indices
are descended from the improved tubes into the bore of the thermometer in the
ordinary way.
".
This claim is a great advantage as it enables this class of thermometer. to.
travel with security & in any condition without the mercury engaging the index or
indices.
ALFRED ERNEST DEAN..

page_text: Improvements in Thermometers.
I, ALFRED ERNEST DEAN, Meteorological Instrument Maker, of 73 Hatton
Garden, London, 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 :-
My invention has reference to a class of thermometers which are constructed with
a detached index of steel or other material for the purpose of registering the
maxima and minima of heat and cold.
These indices are constructed to float on the surface of the mercury in the
thermometer, or are suspended above the mercury if desired and by being brought
into contact with the mercury, become operative.
This class of thermometer as hitherto constructed is liable to derangement in
transit, and it is the object of my present invention to remedy this defect by
providing means whereby the said indices can be isolated or removed from the
indicating portion of the thermometer when it is desired to transport the latter.
My invention is illustrated in the accompanying drawing, which represents the
upper parts of a Six's self-registering maximum and minimum thermometer with my
improvements applied thereto.
The thermometer shown in the drawing is constructed with the ordinary spirit
bulb or reservoir a, with the ordinary capillary tube b, and with the ordinary
herinetically sealed expansion bulb c, and the thermometer is supplied with the
usual thermometric fluids.
Above or beyond the indicating or reading portions of the thermometer I apply
my invention, which consists of a small tube d placed immediately at the ends of
and axially in line with the indicating or reading portions 6 of the thermometer.
These tubes d I place in the interior of the thermometer in such a manner and of
such proportions as to allow the index or indices e to be passed out of the bore
of the thermometer tube or tubes 6 into these tubes when desired to fit the
thermometer for travelling.
To attain this object I construct at the end or ends of the bore of the capillary
tube or tubes b, a cavity or enlargement of suitable dimensions, which may be
immediately touching the reservoir or may be at a short distance therefrom, and in
this cavity or enlargement I place the tubes d in such manner that their ends,
which are opposite the ends of the bore of the capillary tubes b, do not touch the
said ends but are fixed at a short distance therefrom, and the opposite ends of
the tubes d are fixed in any convenient manner, but preferably by blowing, so as to
connect them with the sides of the cavity or enlargement b'or expansion chamber c
as the case may be or as may be found convenient, but preferably such end is
connected all round its circumference with the sides of the cavity or enlargement b¹
or chamber c so as to form a hermetic joint at such part.
These tubes d are formed with a bore of the same, or approximately of the same,
diameter as that of the tubes b, and by their being placed axially in line with the
latter they enable the index or indices of the thermometer to be passed out of
the capillary tubes 6 into the tubes d where they will be retained by the action
of the ordinary springs attached to said index or indices, thus enabling the ther-
mometer to be safely transported by any conveyance, and in such case the cavity
or enlargement and the chamber c receive the disconnected portions of mercury
which may separate from the main body whilst the thermometer is travelling.
These disconnected portions of mercury do not come into contact with the index
or indices previously passed into the tubes d, but they pass into the cavity or
enlargement 6 or chamber c. Thus, when the thermometer arrives at its destination,
it is placed in a vertical position, when the disconnected globules of mercury will

page_text: fall by gravity out of the cavity or enlargement or chamber c and join the main
body, thereby assuming their proper position, and in this manner the index or indices
and the mercury are in no way engaged one with the other. After the mercury
globules have assumed their proper position in contact with the main body, the
index or indices e is or are caused to descend from the tube or tubes d into the
bore of the capillary, tube or tubes where they are used and operate in the usual
manner.
By my invention a great advantage is obtained as it enables this class of
thermometer to travel with security and in any form of case without the mercury
becoming engaged with the index or indices.
It will be evident that my invention is applicable to other thermometers than that
herein shown and described in which a detached index is used.
As a modification the tube d may be secured in the cavity or enlargement b' or
chamber c at one or more parts of, instead of all round, one end thereof, or the
tube d may be placed loosely in such cavity or chamber, in which case the ends of
the said tube are preferably so formed as to form spaces between it and the sides of
the cavity or chamber.. The arrangement above described and represented in the
accompanying drawing is however preferred.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
1. In self-registering thermometers having a detached index, the fixing, within
an enlargement formed at the end of the capillary bore, of a tube axially in line
with the bore and having its entrance end a short distance from the end of said bore,
substantially as herein shown and described and for the purpose stated.
2. In self-registering thermometers having a detached index, a cavity or chamber
adjoining the end of the capillary bore and a tube within such chamber to receive
the index, substantially as herein shown and described and for the purpose
stated.
3. The improved construction of detached index self-registering thermometers,
substantially as herein shown and described and for the purpose stated.
1004
CHID PRO
1004
LAOT
By Harris & Mills,
A. E. DEAN,
23, Southampton Buildings, London, W.C., Agents.