US1081365A

US1081365A - Thermopile.

Info

Publication number: US1081365A
Application number: US79791213A
Authority: US
Inventors: William W Coblentz
Original assignee: Individual
Current assignee: Individual
Priority date: 1913-10-28
Filing date: 1913-10-28
Publication date: 1913-12-16
Anticipated expiration: 1930-12-16

Description

W. W. GOBLENTZ.

THERMOPILE.

APPLIOATION I'ILED OCT. 28, 1913.

Patented Dec. 16*, 1913.

ZSHEBTS-SHEET 1.

W. WQGOBLENTZ.

THERMOPILB.

APPLICATION FILED 0012s, 1913.

Patented Dec. 16, 1913. V

2 SHEETS-SHEET 2.

WILLIAii ooBLnN'Tjz, or wasnme ron, n'rsrmor or oonnmam.

rnnnmomnn.

" Specification of Letters Patent.

Patented Dec. 16,1913.

, Application filed Quota-28.1913. seria no. 797,912,

DEDICATED TO THE PUBLIC.)

To all whom z'fi-may mm.-

Columbia, have invented certain new and I useful Improvements in Thermopiles, of

which the following is a specification.-

This applicationis made under the act of March 3, 1883, chapter 143, (U. S. Statute XXII, page 625'), and the invention herein described and claimed may beused by the Government of the United States or any of its ofiicers'or emplo ees in the prosecution of work. forfthe Unite States orby any person in the United States without'the payment of any royalty thereon.

My lnventio relates to thermopiles and has for ,its lobj ectthe generation of elecftricity directlyfrom heat. mg invention is" to provide an instrument of i A furtherflobject of p p s nature, which, thoughcompact in form and rigid in com auche-n; will be so sensitive to heat that it may be used to advantage in the most re fined physical experiments? p I It. iswell known ,that if two dissimilar metals are joined together and heated at the junction that ahsma'li electric current will tend to flow: This tendency is greater or less, depending upon the temperature at the juncture. For example, if a bismuth wire he connected at each of its ends to a silver wire and one junction isheated above the I other there'will be a tendency for current to flow. If a closed circuit be rovided there will be a continuous flow 0 One application to whichI have putthis device is the comparing and measuring the temperatures of various parts ofthe spec- -trum.

Other objects will be ap arent in the de.

tailed description which follows and from I the: drawings, in which-- current as long. as such difi'eren'ce of temperature is a maintained. Useis made of this well-known principle in this device, the parts being so arranged that the heat rays are utilizedto v a .very considerable extent, producingthe re-' sult that very small differences of tempera "ture may lie-distinguished if a sensitive galvanometer be usedlwi'th this instrument.

- view 'tion part of the box portion cutaway to show the Be it known that I, WILLIAM W. (3013- "LENTZ, a citizen of the United States, and residing lat Washington, in" the District of arrangement of the thermoelectric elements. Flg. 3 shows a modification. Fig. 4 isa;

partly in elevation and partly in seca onigr the hue 44of Fig. 2. -Fig. 5 shows a ont elevation of another embodiment of my invention; Fig. 6 represents a vertical section of Fi 5. Fig. 7 "is a perspect-ive' view of a older with receivers thereon, as used in in device. Fig. 8' shows a plurality of said ho ders and indicates how the receivers of adjacent holders are overlapped. ."Fig'. 9 is a diagram showing one of the ways the thermoelectric elements" may be connected in circuit. i

Similar reference characters refer to similarparts' in all the figures.

Referring first to the diagrammatic show ing of Fig. 1,1 and 2 represent the thermal elements, which .may be any of the substances "common in thermal batteries, such as silver and bismuth. The wires 1 may be silver, while the" wires- 2' may be bismuth.

These. wires are connected, as shown, by gmea-ns'of soldering. The silver and the bisimuth wires are secured to pieces of

good heat conductingmaterial

3, 4, such astin permanent? unions being made by means of solder'. These pieces of good heat conduct-

5mg material

3, 4 are termed receivers for the purpose ofthis description; The receivers 3 are arranged adjacent one another and are imea-nttobe' heated, while the receivers 4 are meant to be shielded from the heat,

i thereby constituting the so-called cold junc- 'tures.-

, asporcelain or hard rubber.

tion, a casing is sh'o-wn, made up of a box portion 5 and a cover 6. Mounted within thebox :portion 5-is the holder 7, consisting of some suitable insulating material, such Mounted on this'holder 7 are the wires 1 and. 2, united by means of the solder to the

receivers

3, 4.

The string of wires and receivers may be mounted by means of pins 8'. The' particular means of mounting is unimportant, but

the recei'vers'3" should be arranged in ali'ne-l ment andshould overlap, as illustrated. The receivers should be backed with a coating of shellac or other suitable insulating material 'in order toprevent a short circuit between the thermal elements. Arranged over a suitable opening in thebox portion 5 refined physical experiments that the receivers on the hot and cold junctures should be symmetrical in area and emissivity, in order that the two sets of junctures may quickly assume the temperature of the surrounding atmosphere when the recesses 3 are not exposed to radiation through the aperture 9.

. In Fig. 3 is illustrated an alternative arrangement of the wires and .the receivers.

.In this arrangement each of the wires 1, 2,

of Fig. 3, is replaced by two wires, 1, 1 and 2, 2, in parallel. These wires may be mounted on pins .8 and joined so as to produce a series-parallel circuit as illustrated; The hot receivers are arranged to overlap as in Fig. 3. The advantages gained by this arrangement are an increase of rigidity due to the fact that the receivers are supported at their two ends. The series-parallelv arrangement of the circuit reduces the internal resistance by approximately one fourth Without decreasing the sensitivity. The symmetry of the hot and the cold junctions is maintained as in the preceding arrangement. By this construction the use of shellac or other insulating material may. be avoided, thus decreasing the heat capacity and emissivity and hence increasing the radi ation sensitivity. The necessary insulative between the successive hot receivers is obtained by slightly displacing them normal to the plane of the curtain. The inside of the casing should preferably be blackened to reduce to a minimum the amount of reflected light. The receivers 4, being shielded from the light and heat rays, are maintained at a lower temperature than the receivers 3, the consequence being'a resultant difference in electromotive force at the ends of the string of elements. These ends are connected with: the terminal binding posts 10', 10. The device may be mounted on any' suitable base 11. Y

One application of the device just described is the comparison' of the different parts'of the spectrum. The arrangement described with the long narrow: aperture illustrated makes comparisons of'thedifi'erent parts of the spectrum. very easy, the

aperture" admitting light from that portion only of the spectrum which it is desired to examine. When the device is being used for this purpose the terminal binding posts 10 will be connected with a sensitive galvanometer;

In Figs. 5 to 9 is illustratedanother embodiment of my invention. A casing is provided by the box 15 and the cover plates 16 and 17, the plate 16 being provided with a suitable opening to permit the entrance of the light and heat rays. The casing may be suitably mounted upon a base 11. Said casing may be rectangular in section, as illustrated, or may be of any other contour desired. Suitably mounted within the box 15 are lugs18, which, with the cross bars 19 and suitable bolts, form the supporting means for the holders 20.. These holders, which-may be of ivory, hard rubber, or any other suitable insulating material, support the elements 1, 2 and the

receivers

3, 4. The

elements 1, 2 are united in strings, as in the embodiment of my invention described above, andare mounted on-three sides of the holders 20, as best illustrated in Fig. 7, being heldfin place by meansof the pegs 21. As illustrated in Fig.7, the receivers 3 on each holder are overla ped, and as illustrated in Fig. 8, the 'recelvers 3 of the various holders are overlapped.

rangement provides an opaque curtain of receivers for the hot junctures. As in the embodiment of my invention described above, the receivers should be backed with a coating of some insulating material, such as shellac, to prevent short circuiting. In this embodiment also the receivers are pref- This arerably blackened to assist in the absorption of radiant energy. Also, the inside of the casing should be blackened to reduce to a minimum the reflection of light. With certain applications of this device it is important thatthe receivers on the hot and cold junctures be symmetrical in area and emis- Y sivity, though of course it is to be understood that the receivers 4 may be omitted if desired.

A high radiation sensitivity may be at tained by choosin the diameters of the two wires forming t e thermal elements, so that the ratio between the heat conductivity aJndh the electrical resistance is the same in In Fig. 9 I show a simple diagram illustrating one wavin which the elements on the various hol ers maybe connected in circuit, in this case the elements of two holders being connected in parallel by means of the wires 23 .to the galvanometer, 22. It

will be evident that the elementsmay be connected in a variety of ways to any translating device desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a thermal generator, a shield provided with an aperture, a series of thermal 7 elements supported behind said shield, said thermal elements being joined to form hot junctures and cold junctures, receivers of heat conducting material joined to said elements at the hot j unctures, said receivers being overlapped to form an opaque curtain arranged behind said aperture.

2. In a thermal generator, a plurality of receivers, wires of dissimilar metals joined to said receivers, a plurality of ends of similar wires being joined near the ends of each receiver and supporting means for said wires.

3. In combination, a plurality of adjacent holders, a plurality of thermal elements, arranged on three sides of each of said holders, said elements being joined to form hot junctures andv cold junctures, heat conducting receivers joined to said elements at the hot junctures, the receivers on each holder overlapping one another to form a curtain on each holder and the curtains on adjacent holders overlapping each other.

4. In combination, a plurality of adjacent holders, a plurality of thermal elements, arranged on three sides of each of said holders, said elements being joined to form hot junctures and cold junctures, said hot junctures being arranged on sides of said holders between the sides on which the said cold junctures are arranged, heat conducting receivers joined to said elements at said hot junctures, the receivers on each holder overlapping one another to form a curtain on each holder and the curtains on adjacent holders overlapping each other to shield the cold junctures from radiation.

5. A. plurality of joined thermal elements, receivers attached to said thermal. elements at certain of the junctures, some of the said receivers overlapping.

In testimony whereof I aflix my signature in the presence of two witnesses.

WM. W. COBLENTZ.

Witnesses:

WALTER B. EMERSON, OHAUNCEY G. PETERS.