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Publication numberUS1676536 A
Publication typeGrant
Publication dateJul 10, 1928
Filing dateAug 26, 1925
Priority dateAug 26, 1925
Publication numberUS 1676536 A, US 1676536A, US-A-1676536, US1676536 A, US1676536A
InventorsKarl A Ferkel
Original AssigneeKarl A Ferkel
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Temperature-indicating means
US 1676536 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

July 10, 1928.





Application filed August 26, 1925. Serial No. 52,623.

The object of my invention is to provide a new temperature indicating means.includ ing a signal covering substance which under change of temperature will disappear and disclose the signal element.- In my pending application, Serial Number 684,308, I have presented a covering matter which, under change of temperature, changes from opaqueness to transparency and thereby presents to view the signal element. The present inven} tion, however, is more like a disappearing curtain for the substance is such that the prc determined temperature will cause it to disappear and uncover the signal or warning element. Another object of my invention is to provide in combination a plurality of similar signal elements, covered with substances which disappear at difierent temperatures, so that there can be successive indications as 0 the temperature increases to warm, hot, and

danger point. These are mentioned as illustratlons, or examples, of the application of the invention for plural temperatures. In order to more fully explain my invention, I have illustrated its embodiment in two slightly difierent forms on the accompanying sheet of drawings, which I will now describe. Figure 1 is a perspective view of one em- 7 0 bodiment of my invention, capable of being attached to an article which is subject to possible overheating, with parts broken awa Figure 2 is a face-view thereon on a smaller scale;

Figure 3 shows the invention as it might a be attached to a buss bar or electric connectin member which might be overheated; and igure 4 shows the invention as applied 40 to a pipe which might. form an important part in a system of oil treatment or distillation and subject to possible overheating. f The invention as here illustrated comprises a body member, 1, of elongated form, having 7 therein three pockets, or chambers, 2, 3 and 4, the back walls, of which are preferably made red, as indicated by the shading. Said ockets have within them the signal or warnmg element, in the present showing, being the words Warm Hot and Dan er..

a a g A covering substance is placed over these words in said pockets and so covers them that they cannot be read. In one case, the substance is one that disappears by decom- 5 5 position, designated 5, and ammonium cyanide is mentioned as an example, this being a chemical which decomposes at v36 C., the products of decomposition being gases which will pass from the pocketior disappear and thus uncover the signal element, which in this case is the word Warm. "The second pocket, 3, has therein the signal or warning element Hot and the covering or curtain matter is designated, 6, and beta ethyl chlorocarbona-te is mentioned as the example, this being a substance which boils at 92 to 94 and leaves the container or pocket and uncovers the signal element; Another substance which might be used is iodine, this being a substance which sublimes or changes from the solid to a gaseous state at a tem perature of 184 C. A further substance or matter which might be used where high temperature can be reached before thedanger point is approached is pure metallic lead, which melts at 327 C. and if this tempera t'ure should be reached, said lead curtain or cover would-melt and run oif of the signal element so as to expose the. same and give the indication or evidence that such high temperature had been reached; -Forpurpo'ses of this application, either the iodine, or pure metallic lead, can be indicated as a cover, 7, in pocket 4, depending on which temperature is desired to be the predetermined temperature at which -the warning or signal should be iven.

In all these cases, it is to e noted that when the predetermined temperature is reached, the covering substance is caused to disappear from the signal element and to uncover and expose said signal or warning element. a

The device may be made with a transparent cover, as 8, over each pocket, and with attaching tears, as 9, 9, or with spring clips,

10, 10, indicated in light broken lines for the purpose of attaching the same, to a flat object., 11, which might be a buss bar or other electric connecting member, or to a pipe, '12, in any system in which the temperatures reached are registered in'said pipe.

While I have shown and described certain embodiments or applications of my inventio'n, it is to be understood thatthese have been shown for explanatory and illustrative purposes, and I do not limit my invention except as I may be limited by the hereto appended claims.

' I claim:

having therein a plurality of di'fierent cham each of said chambers normally hiding from view said signal element, said substances, being capable of changing their form so as to expose to view said signal elements. cov-' ered thereby, and requiring difl'erent tem-' peratures to cause said change in form, whereby to indicate that one temperature has been reached'and another has not been reached.

2., Temperature indicating means consisting of a casing adapted to be placed against a surface Sllb]8Ct to change of temperature, said casing having therein a plurality of different chambers with transparent covers, means'back of said covers to serve as signals whenexposed to view, a substance in each of said chambers and normally covering said signal means, said substances each being capable of change of form to expose said signal means to view and each requiring a difierent temperature to effect such change, whereby said device is operable to indicate that a temperature has been reached between that required to change one substance and that required to change another of said substances.

change in temperature and having a cham-- her, a substance in said chamber which is normally opaque and possessing-the characteristic of changing its form by rise in tem-peraturefrom opaqueness to gaseous form, and a signal element covered by said substance and hidden from. view while said substance remains in its opaque form and exposed to view when said substance changes its form to a gaseous condition by reason of the rise in temperature.

4. A device specially designed to indicate change in temperature including asubstance placed to hidefrom view a signal element, a signal element, said substance releasing itself through a chemical change when a certain temperature is reached, thereby exposing said signal element to view.

5. A device specially designed to indicate change in temperature including a substance placed to hide from viewasignal element, a signal element, said substance releasing itself through a physical change when a certain temperature is reached, thereby exposing said signal element. to view..

Signed at Los Angeles,- Los Angeles County, California, this 21st day of Aug, 1925.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2490933 *Jul 19, 1943Dec 13, 1949Guyot William STemperature indicator
US2750916 *Dec 7, 1953Jun 19, 1956Hanington Charles AHeat indicator for pot handles
US2792484 *Dec 19, 1951May 14, 1957Gen ElectricTemperature measuring and controlling apparatus
US3047405 *Jan 25, 1960Jul 31, 1962William M LauierIndicators
US3329022 *Nov 4, 1963Jul 4, 1967Emerson Electric CoTemperature measurement by sublimation of layers of radioactive material
US3465590 *Aug 22, 1960Sep 9, 1969Sybron CorpThermometer
US3965742 *Oct 24, 1974Jun 29, 1976Rpr, Inc.Digital thermometer and method of manufacture
US4280441 *Jul 6, 1979Jul 28, 1981Akzona IncorporatedTemperature indicator
US4987908 *Jul 18, 1989Jan 29, 1991Philip Morris IncorporatedThermal indicators for smoking articles
US5083815 *Apr 27, 1990Jan 28, 1992Pollard Banknote LimitedHeat actuated game
US5154192 *Jul 18, 1989Oct 13, 1992Philip Morris IncorporatedThermal indicators for smoking articles and the method of application of the thermal indicators to the smoking article
US5622137 *Mar 24, 1994Apr 22, 1997Trans World ServicesTemperature sensors
US7028634 *Jun 25, 2001Apr 18, 2006Eml Technologies LlcWorklight with thermal warning
US20050002439 *Apr 6, 2004Jan 6, 2005Blichmann John R.In-line thermometer
USRE34515 *Dec 24, 1991Jan 18, 1994Pymah CorporationSteam sterilization indicator
DE1573140B1 *May 17, 1966Jun 25, 1970Dabisch WolfgangGlatteiswarneinrichtung
EP0054831A1 *Dec 8, 1981Jun 30, 1982Olympia Werke AgDevice to monitor the condition of a consumable piece of goods
EP0813828A1 *Jun 17, 1997Dec 29, 1997Magic Dreams Cosmetica Infantil, S.L.Depilatory wax case with a heat indicator
U.S. Classification374/162, 116/216
International ClassificationG01K11/12
Cooperative ClassificationG01K11/12
European ClassificationG01K11/12