US1902260A - Heat motor - Google Patents

Description

March 21, 1933. M. PERSONS HEAT MOTOR Original Filed June 15, 1925 M1216?! [We/w 7/4 222/6716 ,41%; g7 a a Pmmd Mar. 21, 1933 UNITED STATES PATENT orrlcr.

LAWRENCE M. PERSONS, O! DES KOINES, IOWA, ASSIGNOB TO COOK ELECTRIC COK- PANY, OF CHICAGO, ILLINOIS,

A CORPORATION 01 ILLINOIS HEAT MOTOR Continuation of application Serial No. 87,091, filed June 15, 1925. This application flied January 10, 1889. Serial No. 331,890. Renewed January 27, 1833.

My invention relates to thermally controlled vapor motors and more (particularly to a vapor motor of this type a apted to be influenced by the thermal expansion of a volatile fluid.

Va or motors constructed in a manner to be in uenced by thethermal expansion of a volatile fluid usually consist of an expansible and contractible vessel cooperating wit a suitable source of heat arranged to heat the fluid and increase the pressure within the vessel. Numerous factors obviously enter into the timing of the movement of the vessel. It has been found that after the initial movement. the vessel continues at a rather rapid rate to expand. but considerable difliculty is ex erienced in avoiding an undesirable lag iiefore the initial movement begins. On the other hand, it is difiicult, due to this initial time lag, to thereafter control the movement in proper timed relation, which is not only desirable but essential in the operation of various regulators.

One of the objects of the present invention resides in the provision of an improve form of vapor motor having a heating tube or boiler in communication with an expansible and contractible vessel and a source of heat which are so arranged as to first rapidly volatilize a limited amount of the liquid, thereb rapidly increasing the pressure within tli e vessel and accelerating t e initial movement of the vessel.

More specifically, this result may be accomplished by arranging the electrical resistance wire or heat coil about the tube or boiler so that the turns of the heat coil are spaced more closely together at the upper end where the volatile liquid first starts to ex and. Accordingly, the pressure in the tn 0 or boiler rapidly increases at the startand thereafter builds up more uniformly and quickly.

I have found that by providing approxi mately three times the number of turns of the heat coil at the upper end of the tube. it is possible to secure complete predetermined expansion of the vessel in one-third of the time heretofore required.

Other objects and advantages of the in vcntion will be apparent from the following description when taken in connection with the accompanying drawings in which:

Figure 1 is a view partly in section and )artly in elevation of a heat motor embodymg my invention;

Fig. 2 is a similar view of another embodiment of my invention; and

Figs. 3 and 4 are also similar views illustrating difierent embodiments of the invention.

In the drawings wherein for the purpose of illustration there are shown several preferred embodiments of my invention, the vapor or heat motor may comprise an expansible and contractible vessel 1 having a volatile liquid therein and atube 2 or boiler in communication with the vessel and which receives a portion of the liquid.

This vessel 1 is preferably shown as comprising a well known form of bellows which readily expands or contracts upon an increase of (pressure therein. Tube 2 is closed at one on posite open end with vessel 1. As to. the specific form of heating device that may be used, it is obvious that the source may be an electrical resistance coil or heating flame conveniently located at or adjacent to tube 2. A heating zone will be provided within tube 2 for heating the volatile liquid and driving it into vessel 1 by volatilization. The pressure within the tube will be gradually increased until the level of the liquid is depressed. whereupon further volatilization stops as the liquid is driven out of the heating zone. It is by this means that a predetermined expansion or movement of vessel 1 may be efi'ectively obtained and held without danger of the pressure within building up to a point where the vessel will burst. In so far as this subject matter is concerned the present application is a continuation of copending application Serial No. 37,091, Filed June 15. 1925.

The vapor motor shown. in Fig. 1 includes the expansible and contractible vessel I having one end closed by a plate 3 to which may be attached a movable actuating rod 4, if this end of vessel is a ranged to be movand in communication at the op-.

able.

A late 5 suitabl closes 0B the opcm of vessel 1, t is plate being prowith an opening Ginto which is seated cup 7 that-may ex tend into-vessel 1. Cup 7 may then extend upward-1y by means oia neck 8. This neck 8 communicates with the lower open end of tube 2 and is hermetically scaled thereto at 9.

A sheet of mica 10, ;or other suitable insulation, may be wrapped about tube'2 so as to provide electrical insulation for an electrical resistance wire or heat coil 12 wound about the tube. Terminal bands 13 and 14 are clamped at proper points along tube 2 to receive the ends of heat C011 12. While I have shown a heat coil of an electrical circuit for furnishing heat or acting as a source of heat for the vapor motor, it will be un derstood that any suitable heating means may be employed.

I find that by applying the heat to tube 2 in a certain manner, the volatilization of the liquid and the consequent expansion or movement of vessel 1 may be accurately con-. trolled under a wide set of conditions. That is to say, the time required to complete the full stroke of a predetermined movement of vessel 1 may be ascertained and accordingly controlled so that the vapor motor may be used in regulators requiring practically any given set of timed operations.

To accomplish this feature, the windings of heat coil 12 may be so spaced as to *concentrate or localize the heat, either initially or during subsetguent operation, along tube 2 and thereby e ect volatilization of a portion of all the liquid in a given time. In the present disclosure, it is found that spacing the windin 'of heat coil- 12 more closely together at t e top of tube 2 causes a relatively quick volatilization of the liquid at the upper end of the column so that re id building up of pressure at this point ta es place. Accordingly, the level of the liquid 18 rapidly depressed to expand or move a ater volume of the liquid into the vessel fi accelerate initial expansion. On the other hand this ra id buildin up of pressure is cop inued ter once s arted, so that posit vide the full s roke may be completed in a relatively sho t time.

In the present instance, I have disclosed three times the number of windings of heat coil 12 along the up r third of the length of tube 2, and by t is arrangement, I am able to obtain complete expansion of vessel 1 in one-third of the time which is normal] required where such spacing is not emp oyed. To illustrate, if tube 2 is three inches in length, the first inch at the top of tube 2 may be provided with fifteen turns, while the remaining lower two inches may each be provided with five turns.

It seems that the aforesaid rapid expandg ti n r m em nt of vessel 1 in less continuous vo at coupling 18 with time is the result of more quickly boiling or heatin a small volume of the volatile liquid at are outset so that with the boilin point once obtained at the level of the co umn .of the li mi in tube 2, more rapid and lization of this column of liquid can be mainta ed until finally depressed into "the vesse or out of theheatin zone.

t will be unders'tood that the specific example given of the manner in which the turnso heat coil 12 are spaced is mere] illustrative of the invention, and accord ingl may be varied'to meet a given set of con itions in the timing of the movement of vessel 1. V v Y In Fig. 2, the embodiment of the invention illustrates a structure" :lvherein vessel 1 is contracted instead of expanded upbn heating of the volatile liquid in tube 2. In this instance, vessel 1 is hermeticall sealed to a plate 15 lower ed e seating, This sion ing in this chamber will compress vessel 1 to move an actuating arm 17 downwardly. Tube 2 may communicate by means of a chamber 19 at one side of so as to receive a housing 16 ereover and enclosing vessel 1.

chamber 19 between vessel 1 and houshousin 16.

Anot er preferred form of the invention is furnished by housin is received so that if desired the fluid in chamber 20 may be used to keep the volatile.

arrangement provides a closed expan-c 16 so that any increase of pressure with} k extending outwardly rom its illustrated in Fig. 3. A chamber 20 is 21in which vessel 1.

liquid in vessel 1 in a liquid state and thereby prevent continued volatilization thereof' after its level has been depressed into vessel 1. This method of maintaining the predetermined expansion of vessel 1 may be used where driving the level of the liquid out of the heating zone in tube 2 is not relied upon. In this device, vessel 1 is hermetically sealed at 24 to plate 25. Tube 2 is also carried by plate 25 and communicates with vessel 1 by means of a hollow tube 26. Plate 25 serves to carry the vapor motor as a unit capable of ready attachment to various forms of regulators.

The embodimentshown in Fig. 4 me. be

likewise carried as a detachable unit,-having tube 2 arranged transversely however.

to the axis of vessel 1. A coupling 30 coo nects tube 2 with the interior of vessel 1.

rangeineut. of these sections, it is impossible for this air to travel back into tube 2. The advantage of removing any such air that may be. trapped in the sealin of tube 2 resides in the fact that initial heating of the liquid is not thereby hindered, inasnulch as the heat may be applied directly to a greater volume of lit uid.

\Vithout furl ier elaboration, the foregoing will so fully explain the gist of my Invcntion. that others may. by applying current knowledge, readily adopt the same for use under varying conditions of service. without eliminating certain features, which may properly be said to constitute the essential items of novelty involved, which items are intended to be defined and secured to me by the following claims.

I claim:

1. A heat motor comprising an expansible and contractiblc vessel having a volatile liquid therein, a heating device therefor and a heat coil wound about said heating device. said heat coil being arranged with the windings at the top of said heat coil more closely spaced to accelerate initial heating of said lit uid.

2. A heat motor comprising an expansible and contractible vessel having a volatile liquid therein, a heating device therefor and a a heat coil wound upon said heating device, the windings of said heat coil along the upper third of the length of said heating device being spaced apart substantially onethird the distance between windings along the remaining portion of said heating device whereby to accelerate initial heating of said liquid.

3. A heat motor comprising an expansible. and contractible vessel having a volatile liquid therein, and a heating device therefor having provisions for generating a greater heat within a limited area of said heating device whereby to accelerate vaporization of said liquid and effect more rapid expansion of said vessel.

4. A heat motor comprising an expansible and contractible vessel having a volatile liquid therein, a. heating device therefore. and a a heat coil wound about said heating device, the windings of said heat coil being more closely spaced at the top of said heating device whereby to accelerate initial heating of said liquid and thereafter more gradual heating to secure rapid expansion of said vessel.

5. A heat motor comprising an expansihlc and contractible vessel and a. tube closed at one end and in communication therewith at the opposite end. said vessel and said tube having a volatile liquid therein, and an electrical heat coil wound about said tube. the windings of said heat coil being spaced more closely together at said closed end whereby initially to heat said volatile liquid at a greater rate.

(3. A heat motor comprising a vessel having a volatile liquid therein and means for heating the liquid for effecting a movement of said vessel. the arrangement of said heat-- in; means being such that a limited amount of said liquid will be lirst volatilized to accelerate the initial movement of said vessel.

7. A heat motor comprising an oxpansible and contractihle vessel having an expansible liquid therein. suitable sup orting means for said vessel. a heating device therefor comprising a substantially closed tube communirating at one end with said vessel, and mounting means arrangin said tube substantially transversely with respect to said vessel.

8. The combination with suitable supporting means. of a heat motor mounted thereon and comprising a closed hodv tilled with an expansible liquid. said body iaving a corrugated section ex ninsihle longitudinall by the pressure of the liquid. a relatively 1nexpansible section having a heating coil surrounding the same, and a coupling member between said sections, said coupling member arranging said sections in relative right angular positions.

In witness whereof, I have hereunto subscribed my name.

LAWRENCE M. PERSONS.

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