US1734205A

US1734205A - Controlling means

Info

Publication number: US1734205A
Application number: US643146A
Authority: US
Inventors: Lewis W Eggleston
Original assignee: American Radiator Co
Current assignee: American Radiator Co
Priority date: 1923-06-04
Filing date: 1923-06-04
Publication date: 1929-11-05
Anticipated expiration: 1946-11-05

Description

Nv. 5, 1929. L. w. EGGLESTON coNTRoLLlNG MEANS 3 Sheets-sheet 1 Filed June 4, 1923 l rf. ...TE

.4 A TTORNE Y.

Nov. 5, 1929. L. w. EGGLESTQN CONTROLLING MEANS Filed June 4, 1923 5 Sheets-Sheet 2 INVENTOR.

Nov. 5, 1929. 1 w. EGGLESTON CONTROLLING MEANS Filed June 4, 1.923 3 Sheets-Sheet 3 y fa,

I N VEN TOR.

Patented Nov. 5, 1929 UNITED srnrla-sv LEWIS W. EGGLESTON, OF BUFFALO, NEW YORK, ASSIGNOR T0 AMERICAN RADIATOR COMPANY, OF NEW YORK, N. Y., A. CORPORATION OF NEW JERSEY CONTROLLING MEANS Application filed .Tune 4, i923. Serial No. 643,146.

My invention relates broadly and generally to new and useful improvements in controlling means, and While it is capable of embodiment in constructions applicable to the control of various elements and mechanisms, it particularly contemplates the provision of simple and eflicient electric circuit-control ling means adapted to be actuated or set in operation by means responsive to a character istic of a gas or liquid, that is, means which may be responsive to hygroscopic, thermostatic, or pressure conditions.

The invention consists in the improvements to be more fully described hereinafter,`

and the novelty. of which will be particularly pointed out and distinctly claimed. I have fully and clearly illustrated the invention in the accompanying drawings to be taken as a part ot' this specification, and wherein- Figure 1 is a sectional View on the line 1-1 of Fig. 2, the section being taken through an enclosing casing, and illustrating in front elevation a preferred embodiment of the invention;

Fig. 2 is a vertical central tion through Fig. 1;

Fig. 3 is a view similar to Fig. 1,but showingcertain parts broken away and others omitted in order to show clearly the position of certain elements during the operation of the device;

Fig. t is an edge view'of a motion-transmitting member, constituting one of the elements of the embodiment shown in Figs. 1, 2 and 3; p

Fig. 5 is a detail view in front elevation of a supporting frame or bracket;

Fig. 6 is a plan view of the supporting frame or bracket shown in Fig. 5;

Fig. 7 is 4a view in rear elevation of a rocking member constituting one of the elements of the structure shown in Figs. 1, 2 and 3;

F 8 is a view similar't the upper part of Fig. 1, showing certain niodifications, the same being taken on` the line 8 8 of Fig. 9;

Fig. 9 is a vertical central section through Fig. 8;

Fig. 10 is a sectional view corresponding longitudinal see- 'to that `shown in Fig. 2, showing another embodiment of the invention;

Fig. 11 is a longitudinal sectional view on the same line as that of Figs. 2 and 10, showing a still further embodiment, and

Fig. 12 is a detail sectional view showing a modified construction adapted to be operated by the pressure exerted by a liquid or gas. i

Referring to the drawings by characters of. reference, 1 designates a back-plate, preferably of insulating material, upon which is mounted a supporting plate 2 spaced from the back-plate to form a space or chamber 3, for a purpose to be presently described, and having a marginal stepped iiange 4 having a marginal bead 5 to set over and receive the marginal edge of the said plate 1. The plate 2 is secured to the plate 1 by suitable screws 2a, extending through openings in the plate 2 and threaded into the plate 1. Mounted on the rear of the plate 1 is a casing 6 secured to the said plate in any suitable manner, and having an opening 7 through which circuit wires or leads may extend.

The struct-ure just described constitutes a suitable support for the parts to be hereinyafter described, and it will be understood that my invention is not limited thereto.

Supported on the front and lower portion of the plate 2 is a rigid bracket-plate 8,

preferably arranged in a vertical plane parallel to the plane of plate 2, and provided.

on its vertical side edges with rearwardly extending ears 9 which pass through open- .ings 10 in the front plate, and are clamped against the walls of said openings to secure the bracket rigidly in place so that the latter is held closely against the said plate 2, as'

shown clearly in Figs. 1, 3 and 5 of the drawings. |The bracket-plate 8 is provided at its lower end with a forwardly extending horizontal arm or platform 11, provided with 'a forwardly extending slot or recess 12, for a purpose to be presently described. At its upper portion, andpreferably integral with one of its side edges, the said plate 8 is provided with affo-rwardly extending arm 13,

preferably arranged in a plane at right angles to the plane of the plate 8, and provided at its forward portion with a lug or projection 14 projecting at right angles to the said arm 13 and overlying and parallel to the plate 8 (see Figs. 1, 2, 3, 5 and 6). The projection 14 is constructed to provide a suitable fulcrum for a motion-transmitting member, preferably in the form of a lever, to be presently described, this provision being afforded by forming the lower edge of said arm with a lf-shaped recess 15 extending inwardly and upwardly from said edge, and the .apex 15 of which recess constitutes the fulcrum for said member or lever, as will be presently described.

As heretofore stated, the switch is adapted to be operated by suitable power means, for exemple, an eXtensible-retractible element, which may be responsive to thermostatic, pressure or hygroscopicl conditions, but'for the purposes of this application l will describe the same in a preferred form as being operated by a thermostatically responsive element in the form of an eXpansible-collapsible corrugated vessel, preferably consisting of a circumferentially corrugated metal cylinder.

nilhis power element, which, as stated, may be thermostatically controlled or operated, is supported upon the bracket-arm 11, heretofore described, and comprises a rigid tube or hollow column 15 having its lower end threaded, as at 17, and projecting through the slot or recess 12, heretofore described, said tube being rigidly secured in place by a nut 18 threaded onto the lower end of the tube below the arm 11 and clamping the saine on the said arm. At its upper end portion the tube or column 16 is provided with a circumferential collar 19, upon which is seated a head 20 of a vertically arranged metallic cylinder 21, said head having a central opening through whichsaid tube extends, the cylinder being secured to the tube riveting down a ortion of the latter, as at 22, upon the upper ace of the head, whereby the latter is clamped rigidly upon the collar 19. rl`he joint between said tube and head at this point is preferably sealed b soldering, so as to be gas and liquid-tight. The cylindrical wall 21 extends downward from the head for a suitable distance, and is provided at its lower edge portion with an outwardly extending circumferential flange 23, to which is secured and sealed the lower end 211 of an expansiblc` collapsible element, comprising a cylindrical corrugated wall or vessel 24 to which is imparted longitudinal resiliency by means of the corrugations therein, as will be apparent from the drawings. The upper end portion of the eXpansible-collapsible element extends above the head 20 for a suitable distance, and is secured and sealed at its edge, as at 25, to a closure-head 26, provided with a central, preferably circular, pocket or recess 27. and with a central opening 28 through which the upper end of the tube or column 16 projects said opening being large enough to permit thehead to slide freely on said tube. Carried by the head-plate 26 is a plunger, which may take a number of'forms within the spirit and scope of my invention, but preferably consists of an inverted cup-shaped cylinder 29, the open end of which is inserted in and snugly lits the recess 27, and is sealed therein by solder or other suitable agent, so that a closed chamber is formed, as shown in Fig. 2. rlhe upper end or head 30 of the plunger is provided with a depression or recess 31 constituting a seat, for a purpose to be presently described.

The upper end ofthe tube 16 is internally threaded, as at 32, to receive a headed plug 33, the head of which overlies and projects laterally beyond the side of the tube 16 to form an annular stop-shoulder 311 with which the head 2G cooperates to limit the upward or expansive movement of the corrugated ezrpansiblecollapsible element.

The plug 321 is provided with a central bore 35, by which communication is established between the bore 16"L of the tube 1G, the interrior of the plunger 29, and thiaugh a slight opening or space between the head 2G and said tube 1G, with the internal chamber 21a established between the cylindrical member 21 and the surrounding corrugated eXpansible-collapsible element. it its lower end the column 16 is open and receives, in the case of a thermostatic device, a filling tube 36, through which the interior of the eXpansible-collapsible element may be evacuated, and a suitable volatile liquid placed therein, after which the filling tube is sealed by pinching together, or otherwise, as may be desired. lt will be understood that the volatile substances selected will depend upon the use to which the device is to be put; for example, in the case of room control, where the device is intended to respond to the ordinary fluctuations of temperature present in a living-room, a suitable amount of ethylchloride may be the volatile liquid employed. lf the device is to be controlled for temperatures other than that existing ordinarily in a living-room, other volatiles, or mixtures thereof, may be employed; for example, for refrigeration purposes'where rero temperature is to be the controlling factor, methylchloride may be employed. lf freezing temperature is to be the controlling factor, carbondioxide may be employed. lt is obvious that other volatile substances may be selected in accordance with the temperature conditions desired to control the device.

lThe expansion or extension of the expansible-eollapsible element just described is employed to transmit motion to improved means for making and breaking a circuit. rl`his means con'iprises a lever, indicated, generally, at 37, consisting of a' plate provided at its llO Y fore described, and on its opposite or rear edge said plate is provided witha lug or pintle 40 having a knife-edge il (see dotted lines, Fig. 1) upon its lower edge portion,f

which pintle 40 projects through an opening 42 in the plate 8. which opening has a V- shaped seat 42a with which the knife-edge 4l cooperates to provide a knife-edge fulcrum on the rear edge of the lever plate. Y It is to be noted that the fulcrums 15a and 42a are arranged on the saine horizontal line.A The plate 37 is provided with an integral arm 37 a extending at an angle thereto and having its end seated in the recess 31, heretofore described, whereby the Alever plate is moved by the thermostatic element when Jthe latter expands. The arm 37 a is preferably provided by striking the same out of the body of the plate 37, as will be clear from F i gs. 1, 2 and 4 of the drawings. The lever plate is arranged to swing in the space between the arm 14 and the main portion of the plate 8, and by providing the oppositely directed knife-edge fulvcrums, that is, one facing upward and the other downward, the lever when subjected to the force exerted by the thermostatic element, and a spring to be hereinafter described, is held to its fulcrums and prevented from rocking out of engagement therewith.

' lhe lever-plate 37 is provided at its upper portion with suitable engaging means, preferably including a rearwardly and upwardly projecting arm 44 projecting through an opening in the plate 2 into the space 3, and carrying an upward projection 45 constituting one of a pair of engaging lugs for engagement with parts to be presently described. The late 37 is provided on one face with a mova le section 46, yieldingly held in engagement with said plate 37 by means of a headed screw 47 passing through said plates and carrying on one end 'a nut 48, an expansion spring 49 being arranged between the section 46 and the head of said screw to provide for a resilient or yielding connection, and to permit slight yielding motion of the plate 46 away from the lever plate 37.

The plate or section-46 is provided with side lugs or projections 49a bent at right angles to the plane of the plate and seated in notches 49b in the side edges of the lever 37, whereby the plate 46 is held against turning movement on said lever.- At its upper end the plate 46 is provided with a rearwardly and upwardly inclined arm 50 having an upwardly directed lug 51, providing with the corresponding

portions

44, 45, heretofore mentic-ned, a recess 52 to receive an engaging device on a member which will now be described:

On the upper portion ofthe plate 2,..and se- .cured rigidly thereto, is a forwardly extendwhich also extends through an opening 57 in the plate 2. Upon the bearing-pin 56 is arranged a rocking member, consisting, preferably, of a horizontal plate 58 having at its rear end a downwardly projecting member 59,

'which is provided with a rearwardly extending lug 60 projecting through an opening in the plate 2 into the space in rear of said plate and which lug is located in the recess 52 heretofore described, whereby the rocking of the lever 37 will serve to rock the member 58 on its bearing-pin 56. The plate 58 is provided on its forward end with a depending arm 61, upon the front and rear of which may be mounted one or more U-shaped spring clips 62, the arms of which are adapted to receive a contact-making and breaking element. ln the preferred embodiment this contact-making` and breaking element consists of\ an evacuated tube 63, preferably of glass, an/dadapted to contain a fluid contact element, such as mercury, shown at 64. At its opposite end portions the element 63 contains pairs of contacts 65, 66, respectively, which, when the tubo is rocked in one direction or the other, are adapted to have the mercury flow into engagement therewith to close a circuit between .the contacts of either pair, as indicated-in Fig. 1 of the drawings, in which the full lines show the tube in the position in which the mercur is in engagement with the air of Y passes when being rocked.

Provision is made for limiting fthe swinging movement of the element 61 so that the lever 37 will be permitted to swing the contact member only far enough to properly immerse the contacts of a pair at one end of the tube 63, and so that the tube will not `be swung so far that the mercury orotheur fluid element will uncover the innermost l.contact of a pair and only immerse the outer contact. The stop means may take a number of forms, but, preferably, the plate 58 is made of such width thatthe end edges 58 thereof will contact with the end portions of theY horizontal member of the bracket 53, thus serving to limit the swinging movement of the member 58 in either direction. The flexible connection of the member 46 with the lever 37 affords a yielding or resilient connection between the lever and the lug 60, so that the member 46 i lll) 67, to which is connected one end 68 of a contractile spring 69, the other end of which is fixed or anchored, as at 70, upon a nut 71, ad- ]ustably threaded on the end of a screw 72, rotatably mounted in an opening 73 in an adjusting device or handle 74 arranged beneath the casing in engagement with the flange 4, and movable transversely thereof. |The lower portion of the flange 4 is preferably arcuate, as at 4, and slidably receives the device 74, th'.- latter having a projection 74rt extending through a slot 74" in the iange. The screw 72 provides convenient means for regulating the tension of the spring 69. The handle 74 may be provided with a suitable indicator 75 adapted to cooperate with a scale 76 on the plate 2, Ain order topermit the adjustmentof the spring to cause the thermostatically or pressure operated device to operate at a desirc-d temperature.

Itis to be noted that the axis of the fulcrum for the lever 37 is located to one side of the longitudinal axis of movement of the power element, and the point of engagement between the lever 37 and the contact-shifting support 1s at a point either on or slightly to one side of the longitudinal axisof movement of the power element. 1t is also to be noted that the connection of the spring with the lever 37 is located above the lever fulcrum, and that the anchorage for the other end of thespring is so located on the opposite side of the said fulcrum, that said spring at all times exerts its force along a line extending at an acute angl to the lever power element. The pairs of contacts 65, 66, in the embodiment shown, are connected, respectively, to pairs of circuit leads 77, 7 8, forming part of a circuit orcircuits leading to any suitable device adapted to be electrically controlled. The leads may be supported and separated by front and rear plates 79, 80, and an inter- :mediate plate 81, of insulating material,

located above the bracket 53. The plates 7 9, 80 are spaced from each other, and supported loosely on a headed bolt 82 rigidly mounted on the plate 2 above the bracket 53. The plates are held against' rotation by a pin 83 fixed at one end on the plate 2, and passing through openings in the saidv plates 79, 80, 81, whereby the plates are movable lengthwise of said bolt and pin.y but are held against rotation. VThe plates 79, 80, 81 arel provided with openings 84 through which the said leads 77, 78'pass, and are held separated from each other, as will be apparentfrom Figs. 1 and 2 of the drawings.

It will be understood that my invention is not limited broadly to any specific form of contact-maker, or to any speciic construction for supporting the circuit wires or leads.

The construction and arrangement of 'parts being as above described, the operation is as follows: It will be understood that the ex pansible-collapsible element has been evacuated to the desired degree and charged with a proper Vquantity of a volatile substance necessary to suit the conditions of use, and to cause the vessel to expand when subjected to certain temperature conditions. The spring 69 is then adjusted 'by means of the movable anchorage to offer sutlicient resistance to the expansible-collapsible element to prevent expansion thereof until -a certain temperature is reached, say, for example, 7 2 F. By setting the anchorage at the mid-position on the scale, the spring will have sufficient resistance to prevent expansion of the element until a. temperature of 72 is reached, and until this occurs will hold the parts in the position shown in full lines in Fig. 1, with the mercury closing the circuit through the contacts 65. Then lthe tempera-ture reaches 72`F. and is slightly exceeded, resulting in sufcient pressure being built up in the expansible-collapsible element to create sutEcient power to overcome the spring resistance, the said element expands and acts on the lever 37 to: Vthrow the same toward the left of Fig. 1.

The movement just described rocks the support 59 to incline the contact-maker in the opposite direction from that shown in Fig. 1, that is, to the position shown in Fig. 3, wherebv the mercurv Hows out of engagement with l. n

contacts 65, breaking the circuit at that point, and into contact with contacts 66, closing the circuit through the latter. So long as the temperature remains at or above that for which the spring is set, the parts will be held ln the position shown in Fig. 3, but as soon as the temperature falls slightly below 7 2o F., the gas in the element 24 condenses, and the spring exerts its force to return the parts to the position shown in full lines in Fig. 1. It will be noted, that due to the fact that the spring extends at an acute angle to said lever and is anchored at its lower end at a point below the fulcrum 39, and is always located to one side of said fulcrum, whenever the power element operates the lever the longitudinal line of the spring will move closer to the fulcrum, and thereby the angle of force at which the spring acts upon the lever is reduced or decreased, thereby reducing the resistance of the spring to said element. By reducing the leverage of the spring at the start of the movement, the expansion of the power element takes place freely -under the internal starting pressure, without regard to the mechanical resistance of the wall of said element, th at is, the inherent resistance of the thermostatic element, due to its resilience. In other words. when the spring is set to prevent operation Yof the device by the power element until a certain temperature is reached, it will' maintain this position until such temperature causes the volatile in the thermostatic device to be volatilized, whereupon only a slight degree of power exerted by the power element in excess of the spring resistance is necessary to overcome the spring, for the reason that the leverage of the latter relative to the lever 37 being reduced the instant the bellows starts to expand, the bellows power quickly overcomes the spring and throws the lever sharply to shift the contact-making device. In this operation, the spring power or resistance is not gradually overcome, but is overcome quickly and suddenly, due to the fact that the swinging of the spring so as to shorten the leverage prevents the spring tension or power building up, and actually reduces it, while the bellows expands.

It will be understood that when the spring is set to cause the device to act to operate at a certain temperature, the spring maintains the expansible-collapsible element slightly collapsed against its inherent spring or resilient tendency to expand, and that as soon as the operative temperature causes the expansiblecollapsible element to expand to have sufficient movement to swing the lever 37, the resistance of the spring, because of the change of the angle of leverage, is reduced, and the natural bellows force tending to expand plus the internal force exerted by the volatilization of the volatile liquid gives sufficient power to quickly overcome the spring. By properly proportioning the force of the spring relative to the force exerted by the expansible-collapsible element, due to its inherent tendency to expand, the device may be caused to operate with a snap action within a small degree of temperature differential. By determining the relation between the spring resistance and the resilient bellows force, the temperature differential to which the device will respond, and the speed with which the operating lever will be moved, may be readily ascertained to suit different conditions of use.

When the lever has been actuated by the power element, as above described, it will beheld in this position so long as conditions maintain the power element extended or expanded, but as soon as conditions result in the collapse or contraction of the-power element, the resistance thereof to the spring is relieved, and the spring acts sharply and quickly to return the lever with a snap movement to normal position, and to hold it in thisposition until it is again actuated by the power element. j

l/Vhen the power element collapses or reftracts, the spring contracts to pull the lever 37 to the position shown in Fig. 1, and as soon as this movement starts, the angle of leverage of the spring on Athe lever is increased slightly, and acting against .the resistance of the bellows returns the lever to initial position with a snap movement. It will be understood thaty at all times there is an internal pressure within the bellows exerted by the expanded volatile material, but it is only the increase or decrease of this pressure relative to a fixed point which results in the operations heretofore described. e

In Figs. 8 and 9 I have shown another arrangement of the support for a contact-maker or switch and the connection between the operating lever and said support. VIn this form of the invention, the main portion of the lever 37 is provided with a pair of vertical, spaced projections or arms 85, in each of'which is threaded an inwardly directed adjusting screw 86, between the inner ends of which is received a lug 87 on a downwardly projected arm 59'd carried by a rocking support 58h, which is also provided with a depending arm 61a having an integral spring clip 88 adapted to receive and hold a contactmaking device 63a, similar in general onstruction and operation to the contact-ma er 63 heretofore described, but with the difference that it is provided with but one pair of contacts, as shown at 89. The spring clip is adapted to grip the contact-maker 63 at its central portion and to be clamped about the same by means of a clamping screw 90 passing through the members 91 of a crimp formed in said clip, as will be clear from Figs. 8 and 9.' In this embodiment of the invention, the rocking member 58b turns on a bearing pin 56a mounted in an opening in the lower end of a downwardly projecting arm 54a on a bracket arm 53, and an opening in the plate 2. In this form the construction and arrangement of the spring may be, and preferably is, the same as that heretofore described, and such description need not be' repeated.

In Fig. l0 I have shown another embodiment in whichthe device is thermostatically operated. In this form, the instrument is supported on a bracket arm 92 having a threaded base 93 adapted to be threaded into the outer end of a collar 94 having a threaded neck 95 to be inserted at a suitable point, subject to the controlling temperature. This collar carries a thermostaticchamber 96 provided with a flange 97 overlying a shoulder 98 in the collar 94:, and clamped thereon by the lower end of said base 93. The chamber or vessel 96 is sealed at its upper end by a suitable plug 98', and the interior thereof is connected to the bore 16a of the tube 16 by means of a tube99 inserted through the sealing plug 98. In this construction, the vessel 96 is located at any point subject to the controlling temperature, and contains a suitable expansible or volatile liquid which, upon heating to a given temperature, exerts its pressure either through expansion or volatilization upon the expansible-collapsible element to operatethe controlling device in the manner heretofore described. In this form the instrument may be employed for controlling any device associated with a hot temperature of the water therein.

In the form shown in Fig. 11, the power element for operating the instrument, as heretofore described, is omitted, and in place thereof said instrument is operated by a device subjected to the pressure characteristic of a gas or fluid. 'In this construction, the instrument may be mounted upon an arm 100 projected vertically from the cover/or cap 101 of a casing 102, having at its lower portion a threaded nipple 103 adapted to be inserted in communication with a suitable source of pressure, for example, -a steam space of a steam boiler. The casing 102 contains an eX- pansible-collapsible element consisting of a cylindrical, circumferentiallj,Tr corrugated metallic vessel 104 having a closed lower end or head 105, and the upper open end of which is connected and sealed, as at 106, to a securing ring or flange 107, the outer edge of which is clamped between a shoulder 108 on the cover or cap 101 and the upper edge of the casing. The eXpansible-collapsible vessel 104 contains an internal reenforcing plate 109 clamped in position against the head 105 by rollingportions of the latter around the edge of said plate, as shown at 110, and upon said plate is a projection 111 slidably arranged within a plunger bar 112 arranged centrally of the vessel. The upper -end of the plunger bar has threaded thereto an eX- tension 113 extending slidably through a guide llflfthreaded into the center of the cover, and the upper end of which projects through the recess 12 in the ybracket 11, and carries at its upper end a thrust-rod 115, the lower end of which is Vadapted to rest upon the bracket 11', and the upper end of which:

is recessed, as at 116, to receive the lower end of the arm. The thrust-rod 1-15s adjustably threaded, as at 117, upon the upper end of the plunger bar, and is adapted to he secured inadjusted position by a set lscrew -118. p The steam or other pressure element flows .into the casing around the eX- pansible-collapsible element 104, and-when the pressure reaches the determined point,

the said element is collapsed to thrust the thrust element upward to actuate the instrument, the operation of the latter being the same as heretofore described; y

Ifjdesired, instead of operating lever 37 thermostatically by the pressure of the gas resulting from volatilization'o material within the vessel 25, I may employ said ves sel as a pressure-responsivedevice. This is accomplished by the arrangement shown in Fig. 12, in which the'sealed filling tube 36 isremoved, and in place thereof a conduit 36L is sealed in the borel of the column 16 and is connected with any suitable source of pressure acting as the controlling or actuating medium.

Whatl claim and desire to secure by Letters Patent of the United States is 1. In a device of the character described,

controlling means, operating means responsive to a characteristic of a gas or fluid, a lever for transmitting motion from said operating means to said controlling means, a spring acting on the lever throughout the movement ot' the latter to oppose said operate ing means, and means for so supporting said spring that the leverage of the latter relative to said lever is automatically reduced when said lever is operated by said operating means.

2.. In a device of the character described, controlling means, operating means responsive to a characteristic of a gas or liquid, a lever for transmitting motion from said operating means to said controlling means, and a spring acting on said lever to oppose said operating means throughout the movement of the lever, said spring having one end connected to the lever and the other end anchored at a point so located that the leverage of the spring relative to the lever is reduced when the lever is operated by the said operating means.

3. In a device of the character described, operating means responsive to a characteristic of a gas or liquid and acting in a direction in a substantially straight line, a lever fulcrumed at a point to one side of the line of movement otsaid operating means and transmitting motion from said operating means to said controlling means, and a contractile spring acting on said lever to oppose said operating means throughout the movement of the lever, said spring having one end connected to said lever and the other end anchored at a point on the opposite side of the lever fulcrum and so located that the leverl age of the spring relative to the lever is varied when the lever moves under influence of the operating means.

4. In a device of the character described, controlling means, operating means responsive to 'a characteristic of a gas or liquid and acting in a direction in asubstantially straight line, a lever ulcrumed at a point to one side of the line of movement of said operating means and transmitting motion from said operating means to said controlling means, and a contractile spring acting on said lever to oppose said operating means throughout the movement of the lever, said spring having one-end connected to said ,lever and the other end anchored at a point on the opposite side of the lever vfulcrum and so located that the leverage of the spring relative to the lever is reduced when the lever swings in one direction, and increased when the lever swings in the other direction. l

5. In a device of the character described, controlling means, a lever for operating said controlling means, operating means responsive to a characteristic of a fluidl or gas for moving said lever in one direction, and a spring opposing operation ofsaidleverby said operating means, said spring having one end connected to the lever and the other end anchored at such` point that said spring is located to one side of said lever and exerts its force along aline at an acute angle to the length of the lever throughout the movement of the latter whereby the leverage of the spring is reduced when the operating means responds to a predetermined condition of the gas or liquid.

6. In a device of the character described, controlling means, a lever for operating said controlling means, operating means responsive to a characteristic of a. fluid or gas for moving said lever in one direction, and a spring opposing operation of said lever by said operating means, said spring having one end connected to the lever and the other end anchored on the opposite side of the lever fulcrum at such point that said spring exerts its force along a line at an acute angle to the length of the lever whereby the leverage of the spring is reduced when the operating means responds to a predetermined condition of the gas or liquid.

7. In a device of the character described, y controlling means, a lever for operating said controlling means, operating means respon. sive to a characteristic of a fluid or gas for moving said lever in one direction, a spring opposing operation of said lever by said operating means, said spring having one end connected to the lever and the other end anchored at such a point that said spring lexerts its force along a line at an acute angle to the length'of the lever, whereby the leverage of the spring is reduced when the operat` ing means responds to a predetermined condition of the gas or liquid, and means for .regulating the power of said spring to vary the point at which the operating means actuates said lever.

8. In a device of the character described, controlling means, a lever for operating said controlling means, operating means responsive to a characteristic of a fluid or gas for moving said lever in one direction, a spring opposing operation of said lever by said op' erating mea-ns, said spring having one end O connected to the lever and the other end anchored at such a point that said spring exerts its force along a line at an acute angle to the length of the lever, whereby the leverage of the spring is reduced when the operating means responds to a predetermined condition of the gas or liquid, and adjustable means for varying the angle at which the -force of the spring is applied to said lever.

9. In a device of the character described, controlling means, a lever for operating said controlling means, operating means responsive toa characteristic of a fluid or gas for moving said lever in one direction, a spring opposing operation of said lever by said operating means, said spring having one end connected to the lever and the other end anchored at such a point that said spring exerts its force along a line at an acute angle to the length of the lever, whereby the leverage of the spring 1s reduced when the operating means responds to a predetermined condition of the gas or liquid, and means for varying the position of said anchorage to vary theangle at vhich the force vot the spring is applied to said ever.

10. In a device of the character described, controlling means, a lever Jfor operating said controlling means, operating` means responsive to a characteristic of a uid or gas for moving said lever in one direction, a spring opposing operation of said lever by said operating means, said spring having one end connected to the lever and the other end anchored at such a point that said spring exerts its force along a line at an acute angle to the length of the lever, whereby the leverage of the spring is reduced when the operatingmeans responds to a predetermined condition of the gas or liquid, and manually adjustable means for varying the angle at which the force of the spring is applied to said lever. y ll. In a device of the character described, controlling means including a rocking member, a lever for operating said rocking member, operating means responsive to a characteristie of a gas or fluid and adapted to op! erate said lever, and a spring acting on said lever to oppose said operating means throughout movement of the lever, said spring having one end connected to the lever and the other end anchored to a point so located that the leverage of the spring relative to the lever 'is reduced when the lever is operated by said operating means.

12. In a device of the character described, controlling means including a rocking member, stop means to limit movement of said rocking member, a lever for Operating said rocking member, operating means responsive to a characteristic of a gas or iiuid and adapted to operate said lever, and a spring acting on said lever to oppose said operating means throughout movement of the lever, said spring having one end connected to the lever and the other end anchored to a point so located that the leverage of the spring relative to the lever is reduced when the lever is operated by said operating means.

13. In a device of the character described, controlling means including a rocking inember, stop means to Vlimit movement of said rocking member, operating means responsive to a characteristic of a gas or fluid, a lever transmitting motion from said operating means to said rocking member, a yielding connection between said lever and said rocking member, anda spring acting on said lever to oppose said operating means, said spring having one end connected to the lever and the other end anchored to a point so located that Aso the leverage of the spring relative to the lever is varied when the lever 1s operated by said operating means.

14. In a device of the character described,-

controlling means including a rocking mem'- ber. stop means to limit movement of said rocking member. operating means responsive to a'charactcristic of a gas or liquid, a leverfor transmitting motion from said operating means to said rocking member, a member yieldingly supported on said lever, said lever and said member supported thereon having spaced engagingidevices adapted to engage said rocking member, and a spring acting'on said lever to oppose said operating means, said spring having one end connected to the lever and the other end anchored to a point so located that the leverage of thespring relative to the lever is reduced when the lever is operated by said operating means.

15. In a device of the character described, a rocking member, a contact-making and breaking device supported on said rocking member to be rocked thereby and comprising a sealed vessel containing contacts and a Huid,

conductor adapted to How into and out of engagement with said contacts, stop means to I limit movement of said rocking member, op-

erating means responsive to a characteristic of a gas or l1qu1d, a lever for transmittmg Vmotion from said operating means to said rocking member, a yielding connection between said lever and Said rocking member, and a spring acting on said lever to oppose said operating means,said spring having one end connected to the lever and the other en d anchored to a point so located that the leverage of the spring relative to the lever is varied when the lever is operated by said operating means.

16. In a device of the character described, a rocking member, a contact-,making and breaking device supported on said rocking member to be rocked thereby and comprisin a sealed vessel containing contacts and a flui conductor adapted to flow into and out of engagement with said contacts, stop means to limit movement of said rocking member, operating means responsive to a characteristic of a gas or liquid, a lever for transmitting motion from said operating means to said rocking member, and a spring acting on said lever to oppose said operating means, said spring having one-end connected to the lever and the other end anchored to a point so located that said spring is at one side of said lever throughout movement of said lever and the leverage of. the spring relative to the lever is varied when the lever is operated by said operating means.

17. In a device of the character described, a rocking member, a contact-making and breaking device supported on said rocking member to be rocked thereby andv comprising a sealed vessel containing contacts and a fluid conductor adapted to flow into and out of engagement with said contacts, stop means to limit movement of said rocking member, thermostatically responsive operating means, a lever for transmitting motion from said operating means to said rocking member, a

rocking member, a contact-making and breakingdevice supported on said rocking member to be rocked thereby and comprising a sealed vessel containing contacts and a fluid conductor adapted to iow into and out of engagement with said contacts, stop means to limit the movement of said rocking member, an expansible-collapsible vessel responsive to a characteristic of a gas or liquid, a lever for transmitting motion from said expansiblecollapsible vessel to said rocking member, a yielding connection between said lever and said rocking member, and a spring acting 011 said lever to oppose said eXpansible-collapsible vessel, said spring having one end connected to the lever and the other anchored Ato a point so located that the leverage of the spring relative to the lever is varied when the lever is operated by said operating means.

19. In a device of the character described,

controlling means, a lever for operating said controlling means, an eXpansible-collapsible vessel responsive to a characteristic of a Huid or gas for moving said lever in one direction, and a spring opposing movement of said lever by said operating means throughout movement of said lever, said spring having one end connected to the lever and the other end anchored on the opposite side of the lever ulcrum at such point thatsaid spring exerts its force along a line at an acute angle to the length of the lever, whereby the leverage of the spring is varied when the eXpansible-collapsible vessel responds to a predetermined condition of the gas or liquid.

20. In a device of the character described, controlling means, a lever for operating said controlling means, an eXpansible-collapsible vessel responsive to a characteristic of la fluid or gas for moving said lever in onev direction, a spring opposing movement of said lever by said operating means, said spring having one end connected to the lever andthe other end anchored on the opposite side of the lever .fulcrum at such point that said spring exerts regulating the langle of leverage of said spring on said lever.

2l. In a device of the character described, a rocking member, a contact-making and breaking device supported on said Arocking member to be rocked thereby and comprising a sea-led vessel containing contacts and a fluid conductor adapted to flow into and out of engagement with said contacts, an expansible-collapsible vessel responsive to a characteristic of a gas or liquid, a lever :tor transmitting motion from said expansible-collapsible vessel to said rocking member, and a spring' opposing operation of said lever by said expansible-collapsible element, said spring having one end connected to the lever and the other end anchored on the opposite side of the lever ulcrum at such pointthat said spring exerts its force along a line at an acute angle to the length of the lever.

22. In a device of the character described, a rocking member, a contact-making and breaking device supported on said rocking member o to be rocked thereby and comprising a sealed vessel containing contacts and a fluid conductor adapted to low into and out of engagement with said contacts, an expansible-collaps'ible vessel responsive to a characteristic of a gas or liquid, a lever for transmitting motion from said expansible-collapsible vessel to said rocking member, a spring opposing operation of said lever by said expansiblecollapsible element, said spring having one end connected to the lever and the other end anchored on the opposite side of the lever fulcrum at such point that said spring exerts its force along a line at an acute angle to thev length of the lever, and manually operable means for setting the position ot the spring to vary the angle at which the force of the spring is applied to said lever.

23. ln a device of the character described, a rocking member, a contact-making and breaking device supported on 'said rocking member to be rocked thereby and comprising a sealed vessel containing contacts and a lluid conductor adapted to iiow into and out of engagement with said contacts, a thermosensitive expansible-collapsible vessel responsive to a characteristic o t a gas or liquid, a lever for transmitting motion from said expansiblecollapsible vessel to said rocking member, and a spring opposing operation of said lever by said expansible-collapsible element, said spring having one end connected to the lever and the other end anchored on the opposite side of the lever fulcrum at such point that said spring exerts its force along a line at an acute angle to the length of the lever.

24e. In a device of the character described, a support, a circuit-controlling devicemounted for rocking movement on the support, a bracket on the support beneath said device, an expansible-collapsible corrugated vessel on said bracket and movable toward and away from said device, a lever ulcrumed on said support to one side of the axial line of movement of said vessel, a part on said lever and engaged by said vessel, the upper end ofsaid lever engaging said device, and a spring opposing t-he expansive movement o said vessel and having one end connected to the upper portion ot said lever and its other end anchored at a point below the ulcrum of said lever, said spring exerting its force along-a line at an acute angle to the length of said lever.

25. In a device of the character described, a support, a circuit-controlling device mounted for rocking movement o n the support, a bracket on the support beneath said device, an expansible-collapsible corrugated vessel on said bracket and movable toward and away from said device, alever ulcrumed on said support to one side of the axial line of movement of said vessel, a part on said lever and engaged by said vessel, the upper end of said lever having means for yieldingly engaging 4 said device, and a spring opposing the expansive movement ot` said vessel and having one end connected to the upper portion of said lever and its other end anchored at a point below the ulcrum of said lever, said spring exerting its Jrorce alongra line at an acute angle to thelength of said lever.

26. In a device of the character described, a support, a circuit-controlling device mounted for rocking movement on the support, a bracket on the support beneath said device,

an eXpansible-collapsible corrugated vessely on said bracket and'movable toward and away from said device, a lever ulcrurned -on said support to one side of the axial line of movement ot said vessel, a part on said lever and engaged by said vessel, the upper end of said lever engaging said device, a spring opposing theexpansive movement of said vessel and having one end connected to the upper portion ot said lever and its other end anchored at a point below the ulcrum of said lever, said spring exerting its force along a line at an acute angle to the length of said lever, and means for regulating the angle of said spring relative to said lever.

27'. ln a device of the character described, a support, a circuit-controlling device mounted for rocking movement on the support, an expansible-collapsible corrugated vessel on said support and movable toward and away Jtrom said circuit-controlling device, a lever fulcrumed on said support to one side of the axial line oi said vessel and having a part engaged by said vessel, the upper end of said controlling means having a range of movel l to the length of the lever throughout movement of said lever. Y

28. In a device of the character described,

ment, operating means responsive to pressure,

. a vlever for transmitting motion from said sure whereby the angle o operating. means to said controlling means, spring means acting on said lever at an acute angle, the angle of application of said spring means on said lever being predetermined whereby the component of force exerted by said spring means on said lever prevents movement of said operating means until the pressure of said operating means becomes equal to or slightly greater than the predetermined opposing componet of force of said spring means, initial movement of said operating means decreasing the angle of application of said spring means on said lever and the force opposing said operating means whereby the pressure necessary to initiate movement of said operating means will move said controlling means completely through its range of movement.

29. In a device of the character described, controlling means having a range of movement, a. sealed chamber containing a Huid and having a resilient Wall, a lever for transmitting motion from said wall to said controlling means, said spring means acting at an acute angle .upon said lever such that a component of force of said spring means opposes and holds said wall immovable until the fluid in said chamber exerts a predetermined pressure slightly in excess of the component of force of said spring means exerted on said wall, said lever being moved by initial movement of said wall at said predetermined presapplication of said spring means on said lever is decreased, and

Athe opposing component of force of said spring means is overcome by said predetermined pressure to -cause said controlling means to be moved by said predetermined pressure completely through its range of movement.

In testimony whereof I have hereunto subscribed my name.

`LEWIS W. EGGLESTON.