US1661346A - Thermostatic controlling mechanism - Google Patents

Description

March 6, 1928.

C.l B. SAWYER THERMOSTATIC CONTROLLING MECHANISM Filed NOV. 1'7, 1922 Patented Mar. 6, 1928.

UNITED STATES PATENT OFFICE.

CHARLES BALDVTIN SAWYER, 0F CLEVELAND, OHIO, ASSIGNR TO THE BRUSH LABO- RATORIES COMPANY, F CLEVELAND, OHIO.

THEBMOSTATIC CONTROLLING MECHANISM.

Application led November-17, 1922. Serial Io. 601,652.

This invention relates to improvements in thermostatic controlling mechanism and more particularly to such as depend for their operation upon the expansion or contraction n of a fluid due to temperature changes,-one A object of the invention being to so construct thermostatic controlling devices, that the same shall be operable to maintain constant,

' the temperaure of a chamber, and so that adlo justment may be effected to maintain constant, any one of a number of different temperatures, and to provide simple and eflicient electric circuit make-and-break mechanism forming part of the controlling mechanism Il and cooperable with the thermostatic ele- -ments thereof to insure accurate control of a temperature regulating device for the chamber, the temperature of which is to be maintained constant.

n A further object `is to provide simple and elicient temperature controlling devices employing fluid as the actuator, with which minute adjustment-s may be effected for any predetermined degreev of temperature, by

changing the ca acity of the system in which the actuating uid is contained, and to so construct and arrange the mechanism that the same shall be useful in refrigerating systems. v

With these and other objects in view, the

invention consists in certain npvel features of construction and combinations of parts as hereinafter set forth and pointed out in the claims.

In the accompanying drawings:

Figure 1 is a view partly in elevation and partly in section showing an embodiment of my invention;

Figure 2 is an end view, and

Figure 3 is a plan view.

In the embodiment of my. invention illustrated in the drawings, I have shown a base block or plate 1, to theunder side of which, the upper edges of metal bellows 2 and 3 are permanently secured by welding, brazing, soldering or in any other manner to effect an air tight connection. The bellows 3 is appreciably smaller in'diameter than the bellows 2 and is located within the latter so that a chamber 4 is formed to' contain an expansible liquid,-such as acetone, for example. A cylinder 5 of thin metal and open at its lower end is disposed between the two bellows to prevent possible interlocking of the folds of said bellows. The base block or plate 1 is provided with a duct 6 which communicates at one end with the chamber 4 between the bellows and with the other end of said duct, one end of a tube 7 is connected,-the other end of said tube having a bulb 8 (preferably of metal) connected thereto and intended to be located in a chamber, 'the temperature of Awhich is to be regulated. The bulb 8, tube 7 and duct 6 and chamber 4 are completely filled with expansible liquid so that no vapor space will be left in the system comprising these elements, and such liquid may be introduced through a suitable opening in the bulb and such opening then permanently closed.

The block or plate 1 and the parts carried thereby may be supported on a yoke or frame 9. The bottom of the bellows 2 is provided with a depending rod or tube 10 which is internally threaded -to receive an adjusting' screw v11,-the latter being loosely mounte in a hole in the cross bar 9@l of the frame 9 and capable of longitudinal movement through said hole. At its lower end, the screw may. be provided, witha manually operable knob/12' to facilitate operation of the same to adjust the capacity of the bellows 2. A spring 12a is disposed between the bottom of the bellows 2 and the cross bar of the yoke or frame 9 and serves to maintain said bellows in its normal working position and adapted. to yield during the operation of the system only when an abnor- A mal pressure occurs therein,-said spring thus acting as a safety device.

In the embodiment of my invention shown in the drawings, a lever 13 is pivotally supported betweenI its ends by a bracket 14 secured to but insulated from the block or plate 1 and this lever has pivoted thereto between its pivotal support and its rear end, a lug 15, the latter lbeing made to engage the insulated upper end of'a rod 16 which passes downwardly through an opening in the block or plate 1 and is made rigid with the bottom 100 of the inner bellows 3.

An insulating block 17 secured tothe base plate 1, carries abinding post 18, to whlch is attached a flat spring 19 and the latter carries a contact polnt 20,-upward motlon 10i of the spring19 being limited by a stop 21.

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'llhe movable contact 22 ot the make-andbrealr mechanism is carried by the tree end portion of a steel spring arm 23 secured to and'in eidect constituting a continuation oli the forward arm ot the lever 13, and between the rear arm of said lever and a bracket 13 supported upon but insulated from the plate 1, a coiled spring 13" is interposed and serves to maintain the lever 13 in operative relation to the rod 16. l

'll`he contacts 20 and 22 may be connected in any "suitable mannerin circuit with a temperature regulating device, but as these details form no part-'ot my present invention, they need not be shown and described herein. llt may be explained however that one circuit wire will be connected with the binding post 1S and the other with a binding posti2l mounted on the base 25 of the bracket 13E.

A magnet 26 (preferably ot the horse-shoe type) may be supported on the end or" ythe base plate l, in such position that `its poles will be in proximity to the steel spring 23,- the latter acting, in effect', as an armature tor said magnet, so that when the contact 22 approaches the 'contact 20, said spring will ycome within the lines yoli torce of the magnet and the contacts caused to close quickly, the force of said magnet being suilicient to torce the spring 19 down against the insulating block 17, which-arrests the travel of the vspring 23 `and prevents it from striking the poles olf the magnet 2t.l

'lWhen the lever'13 is actuated in one di,-- rection by movement of ythe head o1e bellows 3 and the spring 23 has been tiered sumciently, said spring will leave the mag-Y.

net, but the spring 19 will cause contact point 2O to follow-up and remain in contact with contact ppint 22 until restrained by stop 21. k"llhus at the time when the torce exerted by the flexed spring 23 is almost equal to the restraining torce oit the magnet 26, the spring 19 holds the contact points rml-y together and preventsytluttering and consequent destructive sparking which might otherwise occur at this time. lll'urthermore, thespring 19 holds the contact points together until the spring 23 has detinitely lett the magnet 23 and is moving rapidly, so that the circuit is broken suddenly and with a minimum sparking when the stop 21 restrains the motion of the contact point 20. Should the contact points stick together by reason of an unduly large electric current through them, or for any other cause, the pivoted member 13 in conjunction with the spring1 member 23 will constitute a toggle system so that a large torce will be developed tending to slide the contact points addition to the normal separating torce, and 17% this way breakfthem apart and etiect t eir development of dangerous 22---20,v one over the other in separation. lin' normal operation this nanna-aa toggle joint action is likewise present to some extent, andcauses a lateral or sliding motion of the contact points with respect to each other, both on opening and closing, which tends to keep the contact surfaces bright and in good electrical condition. rll"l1e general arrangement of the contact members and their actuating mechanism forms the subject matter of my copenoling application Serial No. 601,653, tiled November 13th, 1922 and entitled Thermostat control mechanism.

lWith the construction and arrangement of parts hereinbefore described, the circuit will be opened upon a tall of temperature in the 'ch-amber, is to be kept constant, and closed when the temperature in said chamber rises, and hence my improvements are eminently adaptable for use with systems of refrigeration. jlf the machine be designed for very low temperatures, the liquid system will beprotected against bursting due to high temperatures during shipment or before installation, by the relieving action of the s ring 12, said spring, while normally retalning the bellows 2 against movement, permitting said bellows 2 to expand in the event ot the pressures by expansion of the liquid contained in the thermostatic system.

With the use enabled to maintain chamber in which the bulb 8 is located, which will be as constant as maybe desired, closenessl of regulation depending on the volume ot the liquid system.

Having fully described my invention, what li claim as new and desire tosecure by lLetters-ljatent, is

11n mechanism of the character described, the combination means including two extensible cup-shaped bellows having their open ends connected to a closing member and having relatively movable closed eids disposed one within the other forming a Huid chamber' betweenthem, and electric lcircuit opening rand closing means connected with the inner bellows.

2. ln mechanism ot the character described, the combination of thermostatic means including two extensible cup-shaped bellows, a plate to which the open ends oit both bellows are connected, one within the other forming a fluid chamber between them, the closed ends of said bellows'being relatively movable, electric circuit opening and closing means connected with the inner bellows, and means for adjusting the volume of the outer bellows.

'3. lin mechanism et the character described, the @nubi/nation of thermostatic means including two cup-shaped bellows,enel

within the othenetorming a Huid chamber between them, a plate towhich the .open ends ot my improvements, ll am a temperature in the lll@ lltlll ot1 thermostatic lll@ lll@

metric capacity of outer bello-ws without changing the capacity of the chamber, and mechanism actuated by movements of the .inner bellows.

5.1n mechanism of the character described, the combination of thermostatic means including two cup-shaped bellows, one within the othery forming a fluid chamber `between them, and connected to ,the same side of a closing plate, a spring retaining the outer bellows in position during normal operation of the mechanism but adapted t0 yield upon development of abnormal pressure, and electrical make-and-break mechamsm operativelyvconnected with the inner bellows. y

6. In mechanism of the character y,described, the combination of a base plateftwo bellows one within the other and having fixed connection with said plate and forming a fluid chamber bet-Ween them, a duct in the base plate in free communication with said chamber, electrical controlling means operatively connected with one end of the inner bellows, a bulb for location in a chamber the temperature of which is to be maintained substantially constant, a tube connecting said bulb with the duct in said base plate, and expansible liquid completely filling said bulb, tube, duct and the chamber between said bellows.

7 lIn mechanism of the character l described, the combination of two bellows, one of said bellows enclosing the other and spaced therefrom, a tube communicating with the chamber formed by said bellows, a bulb communicating with said tube, said chamber, tube and bulb being permanently closed and illed with expansible liquid, an electric "circuit closer and breaker, and connections between said circuit closer and breaker and the inner of said bellows.

8. A thermostat cartridge comprising a support, an extensible cup-shaped bellows havmg its open end secured to saidsupport, a cup-shaped container encasing the first named bellows and secured to the same side of said support t thereby provide a closed chamber between the container and the bellows, meansadapted to adjust the volume of the cup-shaped container without changing its liquid content to thereby control the relative position of Saidbellows with respect to said support, means adapted to maintam said bellows in adjusted position for normal operation of the device, actuated mechanism having limited range of movement controlled by the operation of said bellows, and means permitting an abnormal movement of the bellows resulting from abnormal increase in the volumetric capacity of said cartridge under predetermined abnormal conditions., without affecting a corresponding movement of the extensible portion of the bellows.

9. A thermostat unit comprising a basesa thermostat cartridge carried by the base embodying an extensible bellows of cup-Shape having its open end secured to the support, mechanism actuated by the movement of said extensible bellows over a limited range of movement. a cup-shaped container completely enclosing said extensible bellows and having its open end secured to the support for said extensible bellows and having its side walls spaced from the side walls of said extensible bellows` said extensible bellows being received within said cup-shaped container and adapted to define therewith and with one side of said support,- a closed chamber, liquid adapted to completely `fill said chamber, and normally inoperative releasing mechanism adapted to permit abnormalexpansion of the liquid contained within said chamber independent of the restricted movement'of the mechanism actuated by said cartridge.

10. A thermostat unit comprising a base, a thermostat cartridge carried bythe base embodying, an extensible bellows of cup-shape having its open end secured to the support, mechanism actuated by the movement of said extensible bellows over a limited range of movement, a cup-shaped -container -completely enclosing said extensible bellows and having its open end secured to the support for said extensible bellows and having its side walls spaced from the side walls of said extensible bellows, said extensible bellows being received within said cup-shaped container and adapted to define therewith, a closed chamber, liquid adapted to completely lill said chamber and normally inoperative releasing mechanism adapted to permit abnormal expansion of the fluid contained within the chamber without causing a corresponding abnormal operation of the device controlled thereby.

11. A thermostat cartridge comprising a support, .an Iextensible cup-shaped bellows having its open lend secured to a support, a cup-shaped container encasing the bellows and secured to the same side of said support to thereby provide a closed chamber between the container and the bellows, a plunger actuated by the bellows passingthrough a' closely fitting guide aperture in saidL sup-y port, means adapted to adjust the volume of said lcontainer without changing itsl liquid content to thereby provlde a permanently l sealed thermostat cartridge having arrencartridge adapted to closed bellows and plunger that is adjustable relative to said support.

12. A thermostatically operated circuit making and breaking mechanism comprising in combination a support, switching means adapted to make and break an electric circuit, an extensible thermostatic cartridge mounted. on the support emb-odying a liquid )tilled chamber havlng an extensible portion, means connecting the extensible portion with the switching means, and means adapted to positively adjust the position of the extensible portion ot said chamber relativeto the support `without l changing the volume oit' liquid in the system.

13. lt thermostatically operated circuit making and breaking mechanism comprising.

1n lcombination a support, switching `incans adapted to make and break an electric circuit,.mountcd on the support, a thcrmostatic actuat-e said switching means permanently secured to the support titl .liquid-tight chamber,

and embodying a bellows portion, a cupshaped member having its walls spaced trom the bellows and forming in cooperation with a cover an enclosed chamber, thermally responsive liquid completely filling the chamber, means connecting the bellows with said switching means, and means adapted to positively adjust the position olf' the bellows relative to the support without'l changing the volume of liquid in the thermostatic cartridge.

la. A' thermostatically operated' circuit making and breaking mechanism comprising in combination a support, switching means adapted to make and break an electric circuit, a thermostat cartridge secured to the support and having portions adjustable with respect to said actuating means, said cartridge comprising a bellows anda cup-shaped member spaced from 'said bellows and torming in cooperation with a cover a sealed thermostatic liquid completelytilling said chamber, means operatively connecting the bellows and the switching means, and means adapted to adjust the operative relation between .the bellows and the switching means t'or changing the temperature at which the switching means is actuated by said mechanism without changing the chamber. y

l5. A thermostatically operated circuit making and breaking mechanism comprismg a support, switching means adapted to? switching means,

volume ont liquid in saidV make and vbreak an electric circuit, a thermostat cartridge mounted on the support and adapted to actuate said switching means, said cartridge comprising an eXtensible bellows, a cup-shaped container spaced from said bellows and forming in coopera-v tion therewith an enclosed chamber adapted to be completely filled with a thcrmostatic liquid, a thermostatic liquid completely nlling said chamber, a remotely positioned inextensible chamber of materially greater capacity than said enclosed chamber ,completely lilled with thermostatic liquid, a connecting passageway extending from said container to saidremotely positioned chamber completely filled with liquid, and means adapted to adjust the operative relation between the switch actuating means andthe bellows without changing the liquid content of said chambers and said passageway.

16. A thermostatically operated circuit making and breakingl mechanism comprising a support, switching means mounted on said support and adapted to inake and break an electric circuit, a thermostatic cartridge secured to the support, said cartridge having a portion adapted to engage and actuate said switching means, said cartridge also comprising a yielding bellows, a sealed enclosure partiall formedl by said bellows, liquid complete y lilling the enclosure, and means act-ingindependent of a change in the volumetric content ol the enclosure adapted to change the relation of the bellows to the support for adjusting the relation ot said bellows and said switching means to thereby regulate the temperature at which said switching means is actuated.

175A thermostat electric circuit controller comprising a support, switching means adapted to control an electric circuit, an eX- tensible container adapted to actuate said a second container et materially great/er volume in open communication with the first named container, both ot' said containers and the communicating passage being completely lilled with thermally responsive liquid, and means adapted to regulate the volume ot said lirst container without changing the volume ot liquid in the system in order to change the temperature at which said switching means is actuated.

lln Vtestimony whereof, ll have signed this specication.

CHARLES BALDl/Jllhl SAWYER.

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