April 5 , 1927.
71,623,666
.
K. A. F ERKEL.
TEMPERATURE INDICATING MEANS
Filed Aug. 10. 1926
Innen-¿off
M ü.' ¿JJ
Patented Apr. 5, 1927.-»v
y UNITED* STATES
A i
1,623,666"
PAI-ENT OFFICE.;
man A. :rnnxnnor Los ANGELES, CALIFORNIA.
TEMPERATUR-E-IÑDICATING MEANS. I
Application ñled August 10, `1926'. Serial No. 128,430.
This invention relates to means for indi# transparent material, such as
or it may' A
eating temperature through the use of a have transparent side walls glass,
only.
substance which is naturally opaque, but case, the purpose is the same, mainlyInto.any
use
>which becomes transparent when heated, a container which will support the substance
and opaque again when cool. lThis substance and keep it from the element, and which is»
is used a‘s'a curtainv to hide from lview an sulliciently trans arent as to allow'the ele- "
object, design or element. As long asV the ment to be seen t rough it. Such a container
temperature is unchanged the substance re will be more fully >described below.
,
mains o aque and the object, design or ele»
Another
advantage
in
placing
the
element
10 ment hi den; however, >if the temperature is
outside of the container is that such a device
raised sufficient-ly, the substance will be ren can be used as a pyrometer, or heat meter. ‘
dered transparent and the previously hid@ If energy in the form of radiant heat be al
den object, design or element will become lowed-to strike a body,l a` certain proportion .
- visible therethrough. Upon cooling, the sub of the total vim inging heat energy ‘is ab 70
15
f
stance again becomes `opaque and the object, sorbed. Hence,
p a screen of an opaque sub_
1f
_stance whlch becomes transparent when suili
» -
design or element hidden from view there~
by. By varying the composition of the sub ciently heated
stance, the opaque-transparent changing
v' 20
point may be set at> any desired temperature.
1s placed .at a measured dis- `
tance in front of an element or object and '
the element radiates 'suilicient heat to change f 75
Hence it is possible to use this invention as the substance from an opaque condition to a
a signal to glve warning when a desired tem transparent form and thereby makes the ele
perature. has been reached,.or to use two or ment visible, it is possible to lcomputev the '
25
more such devices as a means tokeep tem temperature of the 'element by` considering
peratures within certainspecified limits.
y the factors involved, such as time required,
I'
In my Patent No. 1,558,153 I disclose a distance between element and substances, the v
hi hly satisfactory means of tempera-ture ‘
opaque-transparent changing -point ofl the
inâication', usin a container` with an element substance, etc, Such a device as this can be f
therein and wit a substance placed in .the used to êindicate the temperature of, very
container covering said element. This sub highly heated objects, which, becauseof their'
stance is normally opaque, but is rendered high temperature„w_ould destroy both con
~transparent when heated. The element or talner and substance if allowed to come in`
'design covered by the substance is `hidden lcontact with them. _
_
_,
.
_
vfrom view as long as the substancerernained '
Another point to be`con'sidered- in con-Y
opaque and is visible only when the substance structingsuch an indica r for use in high
35 is rendered transparent by heat. As p'ointed temperature indication is the expansion of
out 'in that patent, -,such an indicator has the container: One» embodiment, _as de~
many useful applications and is a practical scribedin my previous Patent No. 1,558,153, '
means of temperature indication. '
.
In certain cases, however, it is desirable to
separate the element or signaling member
from actual contact with the substance and
not allow the substance to» cover the element
as .described`in my Patent No. 1,558,153.
45
consisted of a .container having a .metal ' r
back, which was the element, and a' trans
parent» frontal member. These tw'o in com
bination Witha gasket formed the container
of the substance. _At low temperature the
gasket would absorbany difference in ex
This becomes apparent when indicating pansion between the metal and transparent ico
highertemperatures. The substances1 used members. At high temperature,l however,
are c emical compounds, most of which acte it is advisable to construct the entire> con
as reducing, or oxidizing agents, andl when tainer of the same transparent" material,
heated often attack, discolor and even de preferably of one piede, -to eliminate any
stroy the element. In order to overcome this, diliiculties arising from difference in expan
it is necessary to 'lace the element outside
For this reason, a , container, con
the container and ree from all contact with sion.
structed of a single piece of transparent,
-_ thei-.substance._ The Vcontainer inthis case material extends the scope and use of the
must- be. constructed of such transparent ma~ , invention enormously and practically neces
terial that the element can be seen when thel sitates placing the element outside of the
55 substance is in its, ltransparent condîtionî
container. By placing the element outside
The, container may be made entirely of a of the container, the size, shape, location
105
1,623,666
c and type of element used is not limited to
the size or shape of the container. Thev
element may be a surface, object, design or
served it is possible to ascertain the tem
perature of the element. Such a device as
this may be used to determine the tempera
may be ainted on the wall of the container. ture of molten metals and'other exceedlngly
In or er that my invention may be fully hot objects. The container, or containing “
means, may be constructed so as to allow
explained I have illustrated this embodi the
removal of one substance and the placing
ment in three different forms on the accom
of
another
substance with a .different opaque
panying drawing, as follows:
10
changing point in its place.
Figure 1 is a perspective view of my in transparent
In
Figs.
5
and (5, I have shown three indi- =
vention, with section cut away showing one catorsfmounted
in a body, 8, which may be
arrangement of container, substance and a part of a machine
or instrulnent of which
element.
it is desired to know the temperature. Each
Figure 2 is a cross section of the same.
Figure 3 is a perspective view showing indicator has its respective container, 10, 13,
80
the element in a different form and placed and 16, with an opaque substance placed
in- each and designated 11, 14, and 17, each
awa from the container and substance.
of which is opaque at one temperature and
Figure 4 is a cross section of the same.
at a higher temperature, with
Figure 5 shows a plurality of >indicators transparent
an
element
attached
to each and designated
embodied in a body which might form an'
9,
12,
and
15.
The
elements are so placed 85
important part of a machine, with parts
15
to be hidden when the substance is opaque,
cut away showing arrangement of container as
and to be visible when the substance is trans
Y and element.
Figure 6 is .a cross section of thel same. parent. The containers, 10, 13, and 16, are
Referring now in detail to the drawings, of glass, the substances 11, 14, and 17, >being 90
25 I will describe the embodiment of -my in sealed in the glass containers. The ele
9, 12, and 15, are attached to their
vention shown for descriptive purposes. ments,
Figs. 1 and 2 show a container designated respective containers as shown. The opaque
in container, 10, becomes
as, 1.' This container being constructed of substance, 11,`
at a relatively low temperature,
tiiansparent materi‘al enclosing the substance, transparent
30 2, so as to retain it and to keep it from con hence` as heat is applied and the substance,
becomes transparent, and the element,
tact with the element, 3. The container, 1, 11,
9,
becomes
visible, it is known that the tem
' -may be of any shape or size, and may be
made with suitable means for-mounting or perature has reached the point of “cold.”_
attaching to other objects. The element, 3, If more heat is applied, the substance, 14. 100
35 in this embodiment is a design, preferably having a higher opaque-transparent chang
of red, as indicated by the shading with the ing» point, will become transparent and ex
word “Danger” in conspicuous letters. The. pose element, 12, and it will be known that
substance, 2, which 'will be disclosed more the temperature has reached the point of
f‘warm.” In like manner, if more heat is
in detail below,> is opaque at one tempera
4,6
45
»
50
ture, but is transparent at another tempera applied, the”substance, 17, having a still
opaque-transparent changing point,
ture. Hence, when a substance, 2, is opaque, big-lier
wi
become
and expose element,
the element, 3, is hidden. However, if, due 15, and it transparent
will
be
known
that the tem
to a chan e in- temperature, the substance
is rendere transparent, the element becomes perature has reached the point of “ hot.”
visible and a means of temperature indica If the body is allowed to cool, the sub
stances will again become opaque at their
tion is established.
Fig. 3 shows another embodiment of my respective opaque-transparent changing
invention. In this ,case it is shown as a points, and it is possible to observe the cool
means of indicating high temperature, a ing rate of the body, 8, and determine at
type of pyrometer, or heat meter. The sub any time whether the body is “ cold,”
or “hot”
stance, 5, is normally opaque, but becomes “ warm,”
Referring now to a specific substance
110
115
_transparent as. soon as heated to a certain
55
which will function in the manner referred
temperature. This substance has suitable to:
Most chemical compounds have a defi
containin and supporting means, 4, ahd,
7l a contalner having transparent side walls. nite, specific melting oint. Many of them
'fhe element, 6, in this case is an electrical are opaque when in t e solid or crystalline
resistance, of which it is desired to know form and transparent when in the melted,
the tem erature. The` substance is so placed or liquid, form. Such a. compound may be
as to hide from view and to absorb heat used as a substance, for example, benzoic
from the element. If the distance from the acid, CGHSCOZH, is a white, opaque sub
element to the substance, the time it takes stance below its melting point of 123° centi
for the substance to change from opaqueness grade. However, at its melting point, and
~ to transparency and thereby render the above, it is a clear, transparent substance.
element visible, the opaque-transparent Such a compound as benzoic acid can be
changing point of a substance, etc., be ob# used as the substance for such embodiments
20
125
30
1,623,666
as shown in Fi . 1 and 3. In such -an em
8
opaque substances hiding said- elements from v
bodiment as s own in Fig. 5, where a ~View, said substances being such as will turn
plurality of substances is requlred, three from opaqueness to transparency at dif
ferent predetermined temperatures,~ where
stances are m-dinitro-benzene, benzoic acid by said elements may be successively> ex-and benzìlic acid, which change from opaque posed to view, as the different temperatures
to transparent at 96° C., 123° C., and 150° are reached.
.
‘
40
\ compounds which could be used as subf'
C. respectively.
'
v4. Temperature indicating means, includ
45
I do not limit myself to certain com >lng a container, havin transparent walls,
pounds, nor am I` dependent upon the fact an element outside o said container _so
that a substance must melt before it-changes placed as to be visible through said walls, a
from opaqueness to transparency, as a very >substance placed in -said container and nor
satisfactory substance can be made using an mally opaque, said substance/being adapted 50
emulsion. Neither do I -limit myself to any to be rendered transparent under heat,
certain type of container, element or place whereby to expose to _view said element.
application.
'
l
'
A
5. Temperature indicating means, includ
Having thus described my invention, ing a container, having transparent side
what I claim as new ,and desire to secure Walls; an element placed near the outer sur
by Letters Patent is:
face of one of the side walls, visible through
1. Temperature _indicating means, yinclud said side walls; a substance placed in said
ing a substancehaving the property of be container between said side walls so as to
of
20
ing opaqueat one temperature and trans hide from viewv said` element; said sub-_
parent at another temperature; means for stance having the property of being opaque
supporting same; and an element not in con at one temperature and becoming »trans
- f tact with said substance, but so placed as to parent at another temperature.
be hidden when said substance is opaque
and vislble when said substance is trans
parent.
2. Temperature indicating means, include.
30
ing an opaque substance which becomes
transparent when heated and opaque again
when cool; 'a transparent container ’for
same; and an element outside of said con
tainer, visible when substance is transparent,
'
60
»
6. A temperature indicator consisting o
a glass container; an element placed on the
outside but visible through sald container;
65
a substance placed in said container, said
substance chan ing from opaqueness to a
transparency w en heated, and from trans
parency> to opaqueness when cooled, thus
hidlng or exposing said element.
70
Y Signed lat Los Angeles, Los Angeles
but hidden lwhen substance is opaque.
County, California, this 2nd day of lAugust,
-3. Inl a device of the character ,referred 1926.
,
.
to, a plurality of elements, a plurality of
55
>
KARL A. FERKEL.