US2398333A - Thermal-balance-responsive - Google Patents

Description

April 9, 1946.

R. w. SHOEMAKER 2,398,333 THERMAL-BALANGE-RESPONSIVE APPARATUS Filed April 8, 1943 :s Sheets-Sheet 1 April 1946. R. w. SHOEMAKER 2,398,333

THERMAL-BALANCE-RESPONSIVE APPARATUS Filed April 8, 1943 3 Sheets-Shoot 2 2 Edward M ,S/mem/ w' April 9, 1946. R. w. SHOEMAKER 2,398,333

THERMAL-BALANCE-RESPONSIVE APPARATUS Filed April 8, i943 s Sheets-Shoot s lZb/rawd M Skoemakefl Patented Apr. 9, 1946 UNITED STATES PATENT orrlcs THERMAL-BALANCE-RESPONSIVE APPARATUS Richard W. Shoemaker, Woodbury,.Conn., as- Signor to Chase Brass & Copper '00. Incorporated, Waterbury, Conn.. a corporation Application April 8, 1943, Serial No. 482,351

8 Claims.

The present invention relates to improvements in thermal-balance-responsive apparatus, 1. e., apparatus which will respond to radiant heat, convective heat and latent heat of evaporation, and. which will integrate the effects of all thereof into, a unitary result to thereby measure,respond to, or take into account the conjoint mutuallymodifying effects on human comfort ofradiant heat and the other types of heat referred to.

Before proceeding with a description of one mode of carrying out the present invention, attention may here be called to the fact that while a temperature of 70 F. is normally considered to be a comfortable temperature for a room, such temperature cannot be relied upon to provide comfort for persons occupying a room when the it may be pointed out that the human body loses' heat through its skin'to any adjacent surface which is below the average skin-surface temperature (about 83 F.) 'of the person in question. When too great a surface in a room is 'cold (1. e., the mean radiant temperature is too low), an uncomfortable feeling will result to an occupant. In a comfortable room it will usually be found that the wall-surface temperatures are at such an average temperature as to minimize, if not nullify, radiant heat losses from the skin surface of the occupant.

As pertinent in connection with the foregoing and in connection with the discussions here inafter appearing, it may be pointed out that factors affecting human comfort may be broadly summarized as involving air temperature, humidity, airmovement, and radiation-the latter involving radiation both to and from the individual. The average man appears to lose bodily heat under average conditions at the rate of about 400 B. t. u.s per hour when such individual is at rest. Roughly speaking, about 90 B. t. u.sper hour of such heat loss constitute that occasioned by evaporation of bodily moisture (i. e., latent heat of evaporation), which is affected by both the moisture content and the motion of the air surrounding the person. Also, about 190 B. t. u.s

per hour are lost by the average individual due to radiation outwardly from his person, and about 120 B. t. u.'s per hour are lost by the person as a result of convection or air movement.

As will be more fully apparent from the following, the present invention is primarily designed for affecting an electrical translating-device in response to changes in the heat-factors which go to make for and which affect the bodily comfort of human beings. The electrical translating-device referred to'may be of any one of a variety of types and may, for instance, visually indicate changes or serve to indicate changes in heatfactors by controlling an auxiliary or supplemental mechanism. The term indicating" or its equivalent is, forpurposes of convenience of One of the objects of the present invention is to provide a superior apparatus of the character referred to whereby the effects of radiant'heat upon a person may be integrated or gauged conjointly with the effects of convective heat and latent heat of evaporation on such person, to thereby take into account the. major factors affecting personal comfort.

1 Another object of the present invention is to provide a. superior thermal-balance-responsive apparatus which will visually indicate to an observer the conjoint effects of radiant heat, convective heat and the latent heat of evaporation.

A further object of the present invention is to provide a superior apparatus of the character referred to by-means of which the conjoint effects of radiant heat, convective heat and latent heat of evaporation are coordinated to control heating, cooling or other desired apparatus.

Still another object of the present invention is toprovide a superior thermal-balance-responsive apparatus which will respond to radiant heat, convective heat, and latent heat of evaporation in substantially the same manner as an average human being responds thereto.

With the above and other objects in view, as

will appear to those skilled in the art from the' present disclosure, this invention includes all features in the said disclosure which are novel over the prior art.

In the accompanying drawings, in which certain modes of carrying out thepresent invention are shown for illustrative purposes:

Fig. 1 is a face view of one form of detectorunit which may be employed in carrying out the present invention;

Fig. 2 is a view thereof in rear elevation;

Fig. 3 is a view of the detector-unit in side elevation;

Fig. 4 is a top or plan view thereof;

Fig. is an underside view thereof;

-Fig. 6 is a view in vertical central-longitudinal section taken on the line 5-6 of Fig. 1 but on a larger scale;

Fi '7 is a transverse sectional view taken on the line l-l of Fig. 6;

Fig. 8 is a similar view taken on the line 8-8 of Fig. 6; and i Fig. 9 is a view schematically illustrating one form of a complete thermal-balance-responsive apparatus embodying the present invention.

The detector-unit The apparatus shown in the accompanying drawings includes what may be aptly termed a detector-unit" which is generally designated by the reference character it! and which, as will hereinafter appear,'is designed and adapted to detect and respond to changes in any one or all of radiant heat, convective heat and latent heat of evaporation.

The detector-unit above referred to is especially well shown in Figs. 1 to 8 inclusive and includes a block-shaped tank H of rectangular form in elevation and adapted to be mounted against a wall-surface of a room or other en closed space. For purposes of convenient attachment to a wall, the back-face of the tank H v has secured thereto a tapered attachment-plate l2 which is adapted .to fit into a suitable socket (not shown) of conventional and well-known type. At its upper end, th tank II is provided with an externally-threaded tubular neck l3 leading to its interior and provided with a removable closure-cap l4 having a minute ventpassage l5 therein. 1

In the lower right-hand corner of its front wall, the tank H is formed. with a forwardly-projecting lug [Shaving a passage therein communicating with the interior of the said tank. Seat/ed at its lower end in the lug l6 and extending upwardly therefrom into a secondlug i1 is a tubu lar'gauge-glass l8. Like the lug ill, the lu i! has a passage therein communicating with the hollow interior of the tank ll so that water or other fluid within the said tank will indicate a similar level in the gauge-glass i8 when the fluidlevel falls to a level below the under-face of the lug l1.

Brazed or otherwise rigidly secured to the front face of the tank H of the detector-unit I0 is the inner end of a bracket-arm iii. The said bracket-minis formed with a horizontal waterpassage 20 communicating. at its inner end with the hollow interior oi the tank ii and closed at its outer end by a screw-like drain-plu 2i.

Adjacent its. outer or forward end, the bracketarm I9 is formed in its upper face with an LID-- wardly opening socket or recess 22 which is cylindrically contoured to receive the similarly-contoured lower end of a porous cup 23. The said porous cup may be formed of any suitable porous material, though it has been found that porous unglazed ceramic material of a character com- 'monly used in the chemical art is suitable to discharge the function of permitting moisture to seep from the interior to the exterior of the porous cup for purposes as will hereinafter appear.

The lower end of the porous cup 23 is preferably cemented in a watertight manner in the socket or recess 22 in the bracket-arm l9 and has centrally formed in its bottom-wall a vertical water-passage 24 communicating at its lower end with a short vertical water-passage 25 formed in the bracket-arm I9 and communicating at its lower end with the horizontal water-passage 20 therein.

Sleeved over the upper end of the porous cup 23 is the lower end of a tube 26 having soldered or otherwise rigidly secured therein at a point a short distance above its lower end, a centrallyapertured transverse partition-plate 27, as is shown in Fig. 6. The tube 26 and the partitionplate 21 therein may be formed of any suitable material such, for instance, as brass.

The upper end of the tube 25 is sleeved over the lower end of a centrally-apertured headplate 28 and is preferably cemented thereto in a moisture-tight manner. The head-plate 28 just referred to is in turn cemented or otherwise socured in the centrally-apertured lower horizontal arm 29 of a U-shaped bracket generall designated by the reference character 30. The integral vertical base-reach 3| of the U-shaped bracket 30 is skeletonized and bolted or otherwise rigidly attached to the upper-portion of the forward face of the tank H, as is especially well shown in Fig. 6.

Extending parallel with'the lower arm 29 of the bracket 30 is an integral complemental upper arm 32 having its upper face substantially flush with, the upper surface of the upper wall of the tank ll. Enveloping the sides and front of the space between the upper and lower arms 29 and 32 of the U-shaped bracket 30 is a hood 33 which may conveniently be formed of sheet metal and which is retained in place On the said bracket by frictional engagement therewith so as to be readily removable when desired.

Located centrally within the porous cup 23 is a heating-coil 34 which may be formed of any suitable electro-conductive material such, for instance, as nichrome or copper wire preferably insulated by a thin but effective coating of insulatin varnish. Among the many coatings available for insulating electro-conductive wires suitable for use as a heating-coll is a type of enamel known in the art as Formvar.

The respective complemental terminal-leads 35 and 36 extend upwardly from the interior of the porous cup 23 through the aperture in the central portion of the partitiomplate 27. The said complemental terminal-leads 35 and 35 of the heating-coil 34 also extend upwardly through the tube 26 and through the head-plate 28 and bracket 29, and each has its extreme end soldered or otherwise electrically coupled respectively to the forward ends of one of a group of four electric socket-sleeves 38. The said socket-sleeves 38 form a feature of a female electric couplingmember generally designated by the reference character 38 of a type well known in the electrical art. The electric coupling-member 38 is mounted with a force-fit in the forward end of a horizontal tube 40 mounted in the upper portion of the tank I! and extending from front to rear there'through. The respective opposite ends of the horirontal tube 40 are soldered or otherwise secured, in a watertight manner to the respcctive rear and front Walls of the tank I I.

Continuously wrapped around the respective exteriors of both the porous cup 23 and the coaxial tube 26', is' a continuous electric conductor aseas'aa j or wir e formed of a suitable metal or alloy with,

a'densei nsulat-lng layer of varnish. so-called Formvar has been found excellent as an insulation. Copper wire may be used as the electrical conductor, as well as other materials which have their [conductivities markedly changed by changes in temperature. As before stated, the conductor referred to is continuous.butthe group of convolutions thereof which are wrapped around and in contact with'the outer periphery of the porous cup 23, are designated as a group-by therefor in a manner as will more fully hereinafter appear.

The group of convolutions wrapped upon the outer periphery of the tube 26 are designated by the reference character-'42, and will be herein referred to as the radiant-heat-responsive winding." The winding 42 just referred to is so designated for purposes of description inasmuch as it is constructed and arranged to mainly respond to changes in radiant heat emittedtherefrorn or impinging thereon from the surrounding surfaces. The winding 42 is also responsive to convective heat, all in a manner as will also hereinafter. appear.

By wayv ofexample where the; porouscup 23 and the tube 26 are both about 1" .in external diameter, the moisture-responsive winding 4| may comprise about 25 turns of No. 29 copper wire while the radiant-heat-responsive winding As before noted, the windings 4| and 42 are i continuous and, therefore, in effect, the upper end of the winding 4| is integrally connected to the lower end of the winding 42, so that the two said windings are electrically in series. The

end of the upper convolution of the radiant-heatresponsive winding 42 is passed inwardly-through the tube into the interior thereof and consth tutes a terminal-lead 44 complementing the terminal-lead 43 before referred to. From the interior of the tube 26, the terminal-lead 44, passes upwardly through the head-plate 28. and thelower arm 29 of the U-shaped bracket 30 and is soldered or otherwise electrically connected to the remaining one of the four socket-sleeves 3B of the electric coupling-member 39. The moisture-responsiveunit, comprising the winding 4| and the porous cup 23, is preferably light in color to provide a light-colored exterior surface. On the other hand, the radiant-heatresponsive unit, comprising the tube ZBand thev winding 42. is preferably coated with a good grade of dull black paint. By darkening the radiantheat-responsive winding 42 and its support 26, the unit is rendered highly emissive of its own radiant heat and highly absorptive of radl ant hea t' im'pinging thereon from surrounding ob,

iects Conversely, the light-colored moistureresponslve unit. comprising the moisture-responsive winding 4| and the porous 'c'up 2 3, is relatively non-responsive to radiant heat, since as is well known in the art,. light'surfaces; tend-to reflect radiant heat.

The tank may be filled with water or other I suitablefvolatile fluid by removing the closure-cap I4 and introducing the iwat'erthrough the neck l3. .When wateror other suitable volatile fluid is introducedlnto the interior of the tank I I} the same will flow through the water- passages 20, 24 and 25 into the interior of the porous cup 23 for seepageoutwardly through'the latter.

Electrical translating-devices Inconjunction with any suitable detector-unit such, for" instance, as that above described, the present invention contemplates one or more suitable electrical translating-devices, l. e., electrical devices which will translate electric current and changes thereof flowing through the windings '4l and" into desired indications or responses such, for instance, as visual indications', audible indi cations or mechanical responses. v

In Fig. 9 is schematically illustrated the .various coils of the before-described detector-unit l0, together with several electricaltranslatingdevices and related apparatus. For purposes of directly visually, indicating heat conditions inthe vicinity or the detector-- unit l0, an electrical translating-devic infthe form of a 'DArsonval -type microa'mperemeter may be employed as is shown schematically in Fig. 9. The .microamp'eremeter 45 constitutes, an effect, an electrical [measuring-instrument and, as before noted, is preferably in' the form of a DArsonval-type moving-coil permanentmagnet. instrument. The said microamperemeter 45 is provided with an electrically-movable memberor' pointer 46 adapted to sweep over'an arcuate series of graduations 41', which latter may be spaced to represent arbitrarily-chosen units or degreesof human comfort;

Preferably and as indicated in Fig. 9, the cen ter of the series of graduations 41 of the in strument 45, is designatedwith a C" to represent comfortableheat conditions for an average individual. In the instance shown, the graduations to the left of the center graduation of the series 41 are marked with a minus sign to indicate temperature and related conditions below conditions of comfort for the average individual. Similarly,'the graduations 41 to the right of the p center graduationcfthe series 41 are marked with a. plus signto indicate heat and associated conditions which are in excess 'of the requirements of an average person. v 5

As shown, one terminal ofthe electrical translating-device 45 is connected b'y rneans of-a' conductor 48 to the particular one of the four socket-sleeves 38 to which is connected the'trminal-lead 44 '0f--'the radiant-heat-responsive winding 42; The remaining terminal-of'the instrument 45 is connected by means-of a conductor 49 to one output-terminal of a dire'ct-currentsupply unit generally'designated by the reference character 50. The remaining terminal of the direct-current-supply unit 50 is connected by means of aiconductor 5| t0 the particular ur of the four socket-sleeves 38 which has the to minal-lead 43 of the moisture-responsive wih i-- ing 4| connected thereto. 1 1

The two input-terminals of the directecurrenie to compl'emental power-lines 54 and 55. instance shown, the power-lines 54 and 55 may the powcr'line 54.

supply unit 50 have connected thereto 'respec tlvely conductors 52 and 53 respectively leading lead from any suitable source of alternatin current power supply such. for instance, as a commercial alternating-current supply of 60- cycle il-volt characteristics. As thus connected to the power-lines 54 and 55. the direct-current supply unit 50 serves to give a direct-current output and requires no detailed description or illustration herein, since such units are well known in the art. a

For the purpose of energizingthe heating-coil 34. a voltage-reducing transformer generally In the.

designated by the reference-character 5S is-mployed. In a manner well known in the art, the said transformer 56 has its primary connected to both of the power-lines 54 and 55, and the respective terminals of its reducedvcltage secondary are connected to the said heating-coil 34 by means of conductors 51 and 5B. The said conductors 51 and 58 lead respectively to the particular pair of socket-sleeves 38 to which the respective terminal-leads 35'and 36 of the heating-coil 34 are connected.

In addition to'cr in lieu of the electrical translating device 45 or its equivalent; other electrical.

translating-devices may be coupled tothe windings 4i and 42 of the detector unit in or its equivalent to respond to variations in. the re remainingterminal 0f the relay 60 may be con-- nected by a conductor iii to the conductor 49.

Like the D'Arsonval-type microamperemeter 45 before described, the relay 50 is also provided with an electrically-movable member 62 which latter is in the form of a contact-arm rather than in the form of a pointer, as is the case with the part 46. The said contact-arm 62 is adapted to engage with a normally-stationary contact 63 hich is connected by a conductor 64 to one terminal of an elcctromagnet 55 romping; feature of relay generally designated by the reference ch 68. The remaining terminal of the elect conductor 6'! to the power-lino 55 before referred to. The contact-arm 62 is itself connected by a conductor 58 to the complemental power line 54. The electromagnet 65 of the relay S5 is; preferably of suificientlymigh resistance to limit the current flow through the circuit of which it forms a part to value sufficiently low to bereadily handled by the sensitive and relatively-delicate DArsonvnl-type relay 80.

electric motor 72 forming the driving-unit of a fuel-oil burner 73. The remaining terminal of the motor 12 is connected by a conductor T4 to The contact-arm 69 of the relay 68 is connected by a'conductor- 15 to the c t nductor 6.1, which latter is connected into the power-line 55, as before described.

the most accurate performance from the al para tus. the voltages applied thereto should be maintainedat constant predet rmined values in any.

suitable manner.

When the tank l l-lSflllEtd or substantially llllcd with water, the porous cup 23 will have water sup plied to its interior, and such water will seep slow ly outwardly to the exterior periphery of the said porous cup; The heating-coil 34 is so constructed and arranged as, when energized, to maintain the water in the porous cup 23 at a temperature substantially corresponding to the average skinsurface temperature of the average human being or approximately 83 F. When the current-supply is turned on through the direct-current-supply unit current will flow through the seriesconnected windings 4| and 42 and through both the electrical translating-devices 45 and 60.

Under the conditions above referred to, the moisture-responsive winding 4| will have its temperature and hence its conductivity affected by the evaporation of moisture from the surface of the porous cup 23. i. e., when the air surrounding the detector-unit In is relatively dry, moleture will evaporate at a relatively-rapid rate from the surface of the porous cup and thereby cool the winding 41 and thereby improve its conductivity, while conversely, should the atmosphere surrounding the detector-unit Ill be relatively humid. a relatively-small amount of evaporation will take place from the surface of the porous cup 23 with the result that the. cooling effect on the winding 4| will be relatively small.

In addition to being affected by evaporation from the porous cup 23, the moisture-responsive winding 41 will also have its temperature (and hence its conductivity) affected by the motion and the temperature of the surrounding air.

Also under the conditions above described, the

I radiant-heat-responsive winding. 42 will receive nagnet B5 is connected by means of a result that theconductivity of the winding 42 will don to its electromagnet 85, the relay heat by convection from the winding 41 and its associated mounting so that the conductivity oi. the winding-42 will be somewhat affected thereby. As before noted, the radlant-he'at-responsive winding 42 and the outer periphery of the tube 25 is preferably blackened to heighten both the rec'eptivity and emissivity thereof with respect to radiant heat.

accordance with the well-known law deveioped by Stefan Boltzmann relative to radiant heat, a surface either absorbs or loses radiant heat to the surrounding surfaces when its temperature 1 'isless or greater respectively than such surfaces.

From this it follows that when the temperature of the unit comprising the tube 26 and the radiant-heat-responsive winding 42 is less than the temperature of surrounding wall surfaces o he like, the said unit will absorb radiant heat and thereby have its temperature raised with the be lessened. Conversely. should the temperature of the wall surfaces or the like surrounding the detector-unit be lower than the temperature of the winding 42 and its supporting-tube 25, the

said parts will radiate heat outwardly to the cooler surroundings in an effort to reach equilibrium and thereby lowerthe temperature of the windinr: t2 and hence increase its conductivity,

Now inasm 1b as the joint conductivity of the windings 4t and 42 modified by the respecti e temperatures of the said windings, it follows that the electrical translating-instruments 45 and Eli or their equivalents will have their-respective ispe the other in response to any increase or decrease in the current-flow through the said coils 4| and 42.

Inasmuch as the detector-unit is so constructed and arranged that the conductivity of the windings 4| and 42 responds to changes in any or all of radiant heat, convective heat and latent heat of evaporation (which latter is, in turn, affected by the humidity of the surroundings), the detectonunit responds to conditions in substantially the same manner as the human body. These responses of the detector-unit are,

in turn-translated by the instruments 45 and 60' into visual and mechanical indications or actions, respectively, 4

In the instance shown, the translating-device 45 is so calibrated that its pointer 46 will occupy a central position in registry with the symbol C" indicating average human comfort when the combined efiectsof air motion, humidity and'radiation are such as to be comfortable to an average person occupying the same space asthe detector- 7 unit Ill The translating-device 60 is, in the instance shown, so constructed and arranged that should the combined effects of humidity, air motion and radiation be such as to cause an average human being to feel chilly, the joint conductivity of the windings 4| and 42 will, increase thereby permitting a greater current-flow therethrough as well as-through the instrument 60. An increase in the current-flow, as just referred to, will cause the contact-arm 52 to engage with the contact 63. When the contact-arm 62 engages with the contact 63, the electromagnet 65 of the relay 66 will be energized to thus cause the pivotal contact-arm 69 to move into engagement with the contact 10. The engagement of the contact-arm 69 with the normally-stationary contact I0 will 1 close a circuit through the motor 12 of the fueloil burner 13 and thereby start the said burner to restore comfortable conditions. Upon the restoration of comfortable heat conditions, the conductiv'ities of the windings 4| and 42 will lessen, to thereby cause the contact-arm 62 to move away from the contact 63 and thus deenergize the electromagnet 65 of the relay 66; The stoppage of current-flow through theelectromagnet 65 will,

in turn, causethe contact-arm 59 to disengage itselfironi the contact 10 and thereby cut off the energy supply to the motor 12 of the fuel-oil burner 13 I From theioregoing it will be seeen that either or both of the electri'cal translating-device and. to espond to changes in conductivities of the respective windings 4| and 42. It will be further apparent that the conductivity of'the circuit of which the windings 4| and 42 form a part willbe varied in accordance with variation in convective he: radiant heat and latent heat of evaporation, a, cilects of the various types of heat being integrated in their effects upon the conductivity of the circuit and hence in their effects upon the translziting-deviccs, j

he invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characterisi res oi the invention, and the present embodiinm'its are, therefore, to be considered in-all reiliustratire and not restrictive, and all chant, coming within the meaning and equivalcncy range oithe appended; claimsareiintended in be embraced therein.

liclaim: v I l, a thermal balnncoresponsive apparatus including in combination: a radiant-heat-responsive unit including an electrical conductor having a surface highly emissive and highly abant heat received by the unit from its surroundings or emitted by the unit to its surroundings; a moisture-responsive unit exposed to the humidity of the surrounding air and including evaporater-means for containing and evaporating a volatile fluid and having a porous-wall through which such fluid evaporates, and an electrical conductor extending around the porous wall of the said evaporator-means and positioned to have its temperature and hence its intrinsic conductivity altered by variations in the evaporation-rate of fluid passing through the pores of the said porouswall; and an electrical translating-device electrically connected to the respective electrical conductors of both of the aforesaid units and constructed and arranged to respondlto variations in the respective intrinsic conductivities of the said electrical conductors as the temperatures thereof change in response to changes in conditions surrounding the two said units.

-2. A thermal balance responsive apparatus, including in combination: a radiant-heat-responsive unit including an electrical conductor having a surface highly emissive and highly absorbent of radiant heat and constructed and arranged to have its temperature and hence its-intrinsic conductivity altered by variations in radiant heat received by the unit from its surroundings or emitted by the unit to its surroundings; a moistureresponsive unit exposed to the humidity of the surrounding air and including evaporator-means for containing and evaporating a volatile fluid and having a porous wall through which such fluid evaporates, and an electricalconductor extending around the porous wall of the said evaporator-means and positioned to have its temperature and hence its intrinsic conductivity altered by variations in the evaporation-rate of fluid passing through the pores of the said porous-wall; an electrical translatingdevice electrically connected to the respective electrical conductors of both of the aforesaid units and constructed and arranged to respond to variations in the respective intrinsic conductivities of the said electrical conductors as the temperatures thereof change in response to changes in conditions surrounding the two said units; and electrical heating-means located within the said evaporator-means to heat the volatile 'fiuid contained in the-evaporator-means of the said moistine-responsive unit before such -fiuid passes through the porou wall thereof to substantially the skin-surface temperature of the average person.

3. A thermal-balance-responsive apparatus, including in combination: a radiant-heat-responsive unit including an electrical conductor having a surface highly emissive and highly absorbent oi emitted by the-unit to its surroundings; a moisture-responsive unit exposed to the humidity of the surrounding air and including evaporatormeans for containing and evaporating a volatile.

fluid, 'andan electrical conductor associated with the said evaporator-means and electricall connecbed in series with theelectrical conductor of the said radiant-heat-resp nsive unit so that current flowing through the said conductors must also flow through tllC other thereof, the electrical conductor of the said moisture-responsive unit being positioned to have its temperature and hence its intrinsic conductivit altered by variations in the evaporatioir-rate of fluid from the said evaporator-means; an electrical translating-device electrically connected to the respective electrical conductors of both of the aforesaid units in such manner that the current affecting the translating-device passes in sequence through both of the aforesaid series-connected conductors, the said translating-device being constructed and arranged to respond to variations in the respective mutually-modifying conductivities of the said electrical conductors as the temperatures thereof change in response to changes in conditions surrounding the two said units; and electrical heating-means constructed and arranged to heat the volatile fluid contained in the evaporator-means of the aforesaid moisture-responsive unit to a temperature substantially corresponding to the skin-surface temperature of the average person.

4. A thermal balance responsive apparatus, including in combination: a radiant-heat-responsive unit including an electrical conductor having a surface highly einissive and highly absorbent of radiant heat and constructed and arranged to have its temperature and hence its intrinsic conductivity altered by variation in radiant heat received by the unit from its surroundings or emitted by the unit to its surroundings; a mOistl1re-responsiVe unit exposed to the humidity of the surrounding air and including evaporator-means for Containing and evaporating a volatile fluid, and an electrical conductor associated with the said evaporatorsmeans and electrically connected in series with the electrical conductor of the said radiant-heat-responsive unit so that current flowing through one of the said conductors must also flow through the other thereof, the electrical conductor of the said moisture-responsive unit being positioned to have its temperature and hence its intrinsic conductivity altered by variations in the evaporation-rate of fluid from the said evaporatonrneans, the said inoisture-responsive unit being located adjacent thr lower end of the said radiant-heat-responsive unit to transfer-heat to the latter by convection; an electrical translating-device electricall connected to the respective electrical conductors of both of the aforesaid units in such manner that the current. affecting the translating-device passes in sequence through both of the aforesaid series-connected conductors the said translating-device bein constructed and arranged to respond to variations in the respective mutually-modifying conductivities of the said electrical conductors as the temperatures thereof change in response to changes in conditions surrounding the two said units; and electrical heating-means constructed and arranged to heat the volatile fluid contained in the evaporatormeans of the aforesaid moisture-responsive unit to a temperature substantially corresponding to the skln surface temperature of the average person.

5. A thermal balance responsive apparatus, including in combination: a radiant-heat-re sponsive unit including an electrical conductor having a surface highly emissive and highly absorbent of radiant heat and constructed and arranged to have its temperature and hence its inasse s trinsic conductivit altered by variations in radiant heat received by the unit from its surroundings or emitted by the unit to its surroundings;

a moisture-responsive unit exposed to the humidity of the surrounding air and including evap ratormeans for containing and evaporating a volatile fluid, and an electrical conductor associated with the said evaporator-mean and electrically connected in series with the electrical conductor of the said radiant-heat-responsive unit so that current flowing through one of the said conductors must als flow through the other thereof, the electrical conductor of the said moisture-responsive unit being positioned to have its temperature and hence its intrinsic conductivity altered by variations in the evaporation-rate of fluid from the said evaporator-means; an electrical translating-device electrically connected to both of the series-connected electrical conductors of the aforesaid units in suchmanner that the current affecting the translating-device passes in sequence through both of the aforesaid series-connected conductors, the said trans1atins-device having an electrically-movable member constructed and arranged to shift in response to variations in the respective mutually-modifying conductivities of the said electrical conductors as the temperatures of the same change in response to changes in conditions surrounding the two said units; and electrical heatingemeans constructed and arranged to heat the volatile fluid contained in the evaporator-means of the aforesaid moisture-responsive unit to a temperature substantially corresponding to the skinsurface temperature of the average person.

6. A thermal-balance-responsive apparatus, including in combination: a radiant-heat-responsive unit including an electrical ccnductorhav ing a surface highl en issive and highly absorbent of radiant heat and constructed and arranged to have its temperature and hence its intrinsic conductivity altered by variations in radiant heat received by the unit from its surroundings or emitted by the unit to its surroundings; a moisture-responsive unit exposed to the humidity of the surrounding air and including evaporator-means for containing and evaporating a volatile fluid, and a electrical conductor associated, with the said evaporator-means and electrically connected in series with the electri-- cal conductor of the said radiant-heat-respom sive unit so that current flowing through one of the said conductors must also flow through the other thereof, the electrical conductor of the said moisture-responsive unit being positioned to have its temperature and hence it intrinsic conductivity altered by variations in the evaporation-rate ductivities of the said electrical *onductors as the temperatures of the same change in response to changes in conditions surrounding the two said units; and electrical heating-mean constructed and arranged to heat the volatile fluid contained terior of the said fluid-tank, a moisture-responsive electrical winding encircling the exterior of the said porous fluid-container in Position to have its temperature and hence its intrinsic conductlvity altered by variations in the evaporation-.rateof fiuidfrom the said porous fluid-container;- a radiant -heat-responsive unit connectedto the upper end of'the porous fiuid-containerof the. said moisture-responsiveunit and including an electrical winding having a surface highly emissive and highly absorbent of radiant heat and constructed. and arranged to have its temperature and hence its intrinsic conductivity altered by variations in radiant heat received by the radiant-heat-responsive unit from its 5111'- roundings or emitted thereby to its'surroundings; an electrical translating-device electrically connected to the respective electrical windings of both of the aforesaid units in such manner that the current affecting the translating-device passes in sequence through both of the aforesaid series-connected conductors, the said translating-device being constructed and arranged to respond to variations in the respective intrinsic conductivities oi the said electrical windings as the temperatures thereof change in response to changes in ccnditions surrounding the two said units; and an electrical heater positioned within the porous fluid-container of the said moisture-- responsive unit to heat the volatile fluid contained therein to a temperature approximating that of the skin-surface temperature of the average person.

8. A moisture-responsive apparatus including in combination: a fluid-container for containing a-volatile-fluid and having a porous wall through the pores of which the contained fluid is evaporated; an electrical conductor encircling the porous 'wall of the said fluid-container and closely,

contacting the same in such manner as to have its temperature and hence its electrical conductivity altered by variations in the evaporation rate of the fluid through the porous wall of the said fluid-container; and an electrical translating device electrically connected to the said electrical conductor and constructed and arranged to respond to variations in the electrical conductivity of the said electrical conductor as the ternperature thereof changes in response to changes in the evaporation rate of the volatile fluid contained by the said fluid container.

RICHARD W. BHOEMAKER.

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