US1991010A - Switch - Google Patents

Description

Feb. 12, 1935. H. E. BUcKLEN SWITCH Filed April 23, 1952 4 Sheets-Sheet 1 Feb. l2, 1935. H, E. BUCKLEN 1,991,010

SWITCH Filed April 23, 1932 4 Sheets-Sheet 2 Feb. 12, 19315.

' H. E. BUCKLEN SWITCH Filed April 23, 1932 4 Sheets-Sheet 3 m'muz1/ Feb.' 12, 1935.

H. E. BUCKLEN 1,991,010

SWITCH Filed April 23, 1932 4 Sheets-Sheet 4 QMWM @723 f Maw /@J Patentedl Feb. 1.2, 1935 UNITED STATES i swi'ron Herbert E. Tzummarum, Ina.

Application April 23, 1932, Serial No. 607,030

8 Claims.

' The present invention` relates generally to switch mechanisms and is more particularly concerned with a form of switch mechanism useful`in the automatic regulation of apparatus 5 operable to maintain certain temperature conditions, either of heat or cold, in zones; surrounded by dinerent temperature conditions which ailect the temperature of said-zones, as, for example, boilers forv heating plants, refrigeration systems, and the like.

Heretofore it has generally been customary to` regulate furnaces in residences and the like in accordance with the temperature of the room or rooms to be heated. Devices for this purpose generally takev the form of switch mechanism' employing thermostatic elements for turning on and turning ofi the current used in regulating the amount of fuel delivered to thevfurnace or the position of 'the draft or other control members. Other mechanisms, having for their purlpose the automatic regulation of boilers, furnaces, andthe Ilike, involve the disposition of some form of thermostatic switch in the boiler itself for accomplishing the required regulation in accordance with the temperature of the water or other heating medium used in heating the rooms.

Both of these methods` fall far short of securing anything approaching satisfactory regulation. Room thermostats can produce at best only a delayed regulation with the eiect that room temperatures vary over a considerable range, particularly where outside temperatures are apt to change rapidly. The time lag involved in such delayed regulation makes for an inefilcient plant because, in cases where there is a rapid increase in temperature, the re may be kept going longer than necessary, resulting in useless heating of considerable quantities of water or other medium after the need for heat is past or, on the other hand, if the temperature outside falls rapidly the house may bel come chilled before the regulation can be initiated and sumcient heat sent up to the rooms.

With the above factors in mind the present invention contemplates regulating heating systems, not merely in accordance with room temperature or boiler temperature, but in accordance with another factor, namely, the outside temperature. This method makes for a very sensitive control because, in the first place, the heating system is made responsive to outside temperature so that the system is thus prepared in advance for the conditions to be encountered. That. is, by rendering the heating system responsive to both inside and outsidev temperatures, anv change in outside temperature immediately adjusts the heating system even before the temperatures inside the house have been affected by the change in outside temperature. 'I'herefore, the heating system is rendered operative, according to the change in temperature, in advance vof the time this change in temperature 4ailects the temperatures inside the house. The present invention secures this very-desirable resuit in probably the simplest method by controlling the heating system in accordance with both the outside temperature and room temperature.

More specicallyfthe present invention contemplates providing one thermostatic switch with two associated thermal elements, both eapable of exerting a controlling influence upon the switch. One of the thermal elements is subjected to room or boiler temperature while, as to the other thermal element, means are provided for subjecting that thermal element to outside temperatures. Preferably, the two thermal elements are, for practical purposes, closely associated together in the same instrument in order to produce a convenient and compact assembly, being provided, however, with means for bringing outside temperatures into thermal relation with one of the thermal elements.

'Ihe present invention also contemplates as an important feature thereof the provision of con` trol means which embodies three thermostatic means, one subjected to room temperature, one subjected to boiler temperature and one subjected to outside temperature, this affording a control mechanism which is admirably adapted to meet every change of temperature condition which the heating system may possibly encounter.

These and other objects of the' present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings, in which:

Figure 1 lis a. sectional view taken through a thermostatic switch of the tilting contacter tube type in which the contactor element is positioned according to the cumulative effect of the temperatures of two thermal elements;

Figure 2 is a section taken along the line 2-2 of Figure l;

Figure 3 is a diagrammatic sketch showing the disposition of the instrument illustrated in Figures l and 2 on a heating boiler and arranged in. serial relation with a second instrument in the form of a room thermostat;

Figures 4 and 5 are sectional views of a modified form of instrument;

Figure 6 is a fragmentary section taken along the line 6-6 of Figure 5;

Figure '7 is a diagrammatic sketch illustrating the installation of the instrument shown in Figures 4 and 5;

Figure 8 is a diagrammatic sketch illustrating a slightly different arrangement of the instruments 'shown in Figure 7, the -difference being that where in Figure 6 the two separate instruments were arranged in series the instruments shown in Figure 8 are arranged in parallel;

Figure 9 is a front view, partly in elevation and partly in section, illustrating the principles of the present invention as embodiedin Va room thermostat wherein two thermal elements are operatively connected together, one beingl subjected to room temperature while the other is subjected to outside temperature;

Figure 10 is a section taken along the line 10-10 of Figure 9;

Figure 11 is a diagrammatic sketch illustrat-a ing the installation of the instrument illustrated in Figures 8 and 9 and showing the relation between the instrument and the heating system;

Figure 12 is a front elevation of a refrigerator illustrating the application of the principles of the present invention to an apparatus of this ype;

Figure 13 is an enlarged fragmentary detail, showing the disposition of one thermostat within the cooling unit of a. refrigerator and another thermostat exterior of the refrigerator and subjected to the temperature of the room or space in which the refrigerator is placed;

Figure 14 is a view similar to Figure 12 but showing a slightly modified form of arrangement of the thermost'ats; and

Figures 15 and 16 are diagrams' illustrating the electrical connections employed in Figures 12 and 14, respectively.

Referring now more particularly to Figures 1, 2 and 3, the reference numeral 10 indicates a thermostatic switch for boilers and the like embodying the principles of the present invention. In Figures 2 and 3 the boiler is indicated at 11 and the instrument 10 is seen to comprise a cylindrical casing 12 adapted to extend into the water space of the boiler 11. At its outer edge the casing 12 is threaded into a fitting 14 secured in any manner to the boiler 11, as by cap screws 15, by which a leak tight joint is secured. `The fitting 14 carries a second casing or housing 17 which, in the form shown in Figures 1 and 2, is disposed in generally upright position and is of substantially cylindrical formation having planar sides 18 and 19.

The two interconnected casings 12`and 17 serve to enclose a switch shaft 21. One end of the shaft 21 is journaled in a boss 23 secured' to or forming a part of the inner end of the casing 12 while the Aother end of the switch shaft 21 is rotatably supportedwithin a shiftable sleeve 24, the sleeve being in turn movably supported in the tting 14, as by packing 'or journal means 26.

A thermostatic coil or thermal'element 30 is disposed within the casing and has one lend secured to a collar 31 fastened on the shaft 21 while the other end 32 is anchored to the shiftable sleeve 24 by means of a small screwv 34 or the equivalent.

` A second thermal element 35 is operatively mounted within the second casinl 17. This Second thermal element is preferably in the form" of a bimetallic strip with one end securely anchored in the upper part of the casing 17 by means of a stud 37 riveted or otherwise securely fastened. The opposite end of the thermal element 35 ,is connected to the switch shaft 21 by virtue of its operative association with an arm 40 secured to the shaft 21. The arm 40 isa part of a collar 41 carried by the switch shaft 21. This shaft also carries a plurality of .spring fingers 43 to removably receive a mercury switch contactar tube 45 of conventional construction.

- As is usual in this form of device, the switch tube 45 includes contacts 49 and 50 and flexible leads or conductors 52 and 53 having their upper ends secured on a small panel or strip 54. The housing 17 is suitably apertured, as at 55, to. provide for the leading out of the conductors 58 and 59 connected, respectively, with the conductors 52 and 53.

In order to provide for manual adjustment of the instrument 10 the shiftable sleeve 24 carries a disk 60 to which is secured an adjusting hand 61, one end of which is movable over a dial or indicator plate 63. Thus, by shifting the sleeve 24 the point of anchorage of the thermal element 30 can be changed, .thereby changing the temperature at which the contractor. tube 45 will be tilted to either make or break the connection between the contacts 49 and 50.

The thermal element 30 is subjected, in this modification, to the temperature of the water in the boiler 11 -while the thermal element 35 is subjected to the temperature of the'outside air. This .las't named feature is accomplished vby providing conduit-means in the form of a tube 70 leading from a point outside the b'uilding into the interior of the casing 17. This tube or conduit 70 may be any suitable size or form and it may openl into the casing 17 at any pointA but preferably it should open somewhere adjacent the thermal element 35. The top of the casing 17. is provided with vent means in the form of a stack 71 carrying a hood 72,to prevent the entrance of dust, dirt and the like into the casing 17, and a damper or valve 7'4 adjustable by means of a crank handle 75. Since the casing 17 is disposed somewhere .adjacent the boiler where the surrounding' air is somewhat Warmer than outside air a circulation will be established which will draw in cold air through the conduit 70 into the casing 17 and out past the valve 74 in the stack 71.A This constant circulation of outside air into the casing 17 thus subjects the thermal element 35 to a temperature substantially equal to the temperature of the outside air. Where the casing 17, in which 'the thermal element 35 is disposed, is subjected to outside temperatures, the interior of the casing 12, in which is disposed the first thermal element 30, is subjected to the temperature of the heating medium in the boiler. The thermal element 35 is preferably so arranged that it bears at all times against the arm 40 butwith greater or less force depending on outside temperatures. 'Ihe thermal element 35 is preferably so arranged that with an 4increase ,in temperature the element tends to move to the left in Figure 1 to thereby relax, to an extent dependent upon the temperature change, its force exerted against the arm 40 which normally tends to swing the same in a clockwise direction. The other thermal element 30 is arranged, on the other hand. so that with an increase in Lus CFI

vby an electric motor 81.

temperature this Aelement tends to swin'g the contactor tube 45 in a counterclockwise direction, as viewed in Figure 1.

It will be recognized that each of the thermal elements 30 and 35 are formed of resilient ma- ,n the position shown in Figure l to close the cir- `cuit 49-50. Now if, at this time, the outside temperature should suddenlyvrise the thermal element 35 would relax a certain amount and the force exerted by it upon the arm 40, and hence upon the shaft 21, would be lessened. The force of the other thermal element 30, which before the temperature rise was opposed by the force of the thermal element 35, would thereupon be released to an extent dependent upon the relaxing of the element 35, so that if the temperature rise outside were great enough the switch tube 45 would actually be tilted in a counterclockwise direction as viewed in Figure l so that the circuit would be broken at 49-50 even though the temperature in the boiler would otherwise be sufliciently low to normally cause the switch 45 to close the circuit. In effect, therefore, the present invention contemplates using two thermostatic elements and so arranging them that for a given temperature each exerts a force tending to oppose the force of the other one, and hence if the force of one is relaxed by a temperature change the force of the lother becomes immediately available to shift the switch tube. Obviously, if both elements are relaxed an equal amount the switch tube will notbe shifted.

In this way, therefore, the switch tube 45 is disposed under the cumulative effect of the temperature of the water in the boiler l1 and the temperature of the outside air.

Figure 3 illustrates a preferred form of installation embodying the instrument described above. As illustrated in this figure, the boiler 1l is fired by means of a fuel injector 80 driven Leads 82 and 83 are connected with the motor 81 and lead 82 extends to the instrument l and is directly connected with the conductor 58 in the instrument. The other lead 83 extends directly to a line switch 85. The other connectorv 59 in the housing 17 is connected to a conductor 87 which extends `to a room thermostat switch 90 of conventional construction. As illustrated this room thermostatic switch includes a mercury switch tube 91 and a thermostatic coil 92 responsive to temperatures in the room. The switch liquid contained in the contactor tube 91 is adapted to close the circuit from the conductor 87 to a second conductor 94 which extends from the thermostatic switch 90 to the line switch 85.

The operation of the structure described above is as follows:-.

When the line switch 85 is closed and both switch tubes 45 and 91 tilted to close their repective circuits current is sent through the motor 81 whereby fuel is delivered to the boiler 11. For purposes of illustration only, the arrangement indicated in Figure 3 is representative of conventional oil burner installations in which fuel oil is delivered into thel boiler 11 by means of the'fuel injector 80. As far as the present invention -is concerned, however, the device 80 and motor 81 is representative of any form of means for varying the rate of combustion within the boiler and, as such, these parts may be considered equivalent to any form of fuel injecting means or draft producing or varying means.

The three thermal elements 30, 35 and 92 are each responsive to different temperature conditions, element 30 being responsive to the temperature of the water in the boiler, element 35 being responsive to the temperature of the outside air, and element 92 being responsive to the temperature of the room in which the instrument 90 is disposed. Under normal conditions the instrument illustrated in Figures 1 and 2 will serve to maintain room temperature substantially constant. For example, assume that the device 80 is delivering enough fuel or enough draft to the furnace 11 to maintain the water therein at a substantially constant temperature, assuming, of course, that under these circumstances the various radiators throughout the building will have suflicient capacity to dissipate the heat formed to produce the uniform heating of the house. As stated above, a circulation of cold air is caused to flow from the outside into and through the conduit 70 into y the interior of casing 17 in which the thermal element 35 is positioned. As long as the outside temperature remains substantially constant the boiler 11 will be operated to keep the rooms at uniform temperature. Now if for any reason the outside temperature suddenly falls this temperature change is immediately impressed upon the thermal element 35 which, in cooling, will exert a greater force against the arm 40 tending to swing the switch tube 45 to close the circuit at 49-50. This automatically starts the motor 81 thereby producing more heat to offset the lowered outside temperature, unless at this moment the temperature in the house is warm enough so that for the moment no additional heat is required. As soon, however, as the room temperature falls slightly the switch 91 will close and since the switch tube 45 has already been tilted by virtue of the drop in temperature of the outside air, the motor 81 will be started and will continue until the rooms become sufilciently warm to cause the thermal element 92 to break the circuit between the conductors 87 and 94, or until the temperature of the water in the boiler is raised sufficiently to cause the element 30 to overcome the force of the cooler element 35 to break the circuit at 49-50. With respect to the latter operation, it will be apparent that when the outside temperature is lower a higher temperature of water will be i at 49-50 with a greater force than when vthey outside temperature is somewhat higher. In this installation, therefore, the instrument 10 is at all times under the control of the room thermostat 90. This feature of controlling the boiler 11 in accordance with the two factors, room temperature and outside air temperature, I consider as a very important point of the present invention. Room thermostats and boiler thermostats are, in themselves, old but so far as I am aware it is new to modify their operation or controlin accordance with the changes in temperature of the outside air.

YFigures 4 and 5 illlustrate a somewhat different type of instrument but one which is, for practical purposes, substantially the same in operation as the instrument illustrated in Figures 1and2. InFigures4and5apairofintercylinder or sleeve 102. The casing 100 is disposed in one wall of the boiler 11 and in this casing is disposed a thermostatic coil 104. One

end of the coil 104 is anchored to the'casing 100, as at 105, while the other end is xed to a collar 108 secured to the inner end of a switch shaft 110 which is journaled Within the casings and 101. As in the form illustrated in Figures 1 and 2, the inner end of the switch shaft is journaled within a boss formed in the boiler thermostat -casing 100.

.the casing While the other end of the thermal element is screw connected to an arm 11'7 fixed in any manner desired to the outer end of theswitch shaft 110, this end being journaled for rotation in the second casing 101. 'Ihis end of the switch shaft also carries a switch tube containing a contact making and breaking liquid in the usual manner. The contacts within .theswitch tube 120 are connected by means of flexible leads 121 and 122 to conductors 123 and 124 which lead, as shown in Figures 6 and '1, one to the motor 8l and the other to the line switch 85.

The interior of the casing 101 is subjected to the temperature of the outside air, and for this purpose a conduit is provided leading from the outside of the building and terminating in the lower portion of the casing 101, as best shown in Figures 4 and 5. To provide for a circulation through the conduit 130 the upper part of the casing 101 is provided with a stack 131 including a hood 132 and a valve o'r damper 133. Cold air from the outside is drawnin through the conduit 130 .and is thereby brought into thermal relation with ,the thermostatic element 115. In this Way the contactor tube 120 is disposed under the cumulative control of the thermostatic elements 104 and 115. Connected between the line switch 85 and the motor 81 on the side opposite the connection 124 is a pair of conductors 138 and 139 between which is disposed a room thermostat 140 of conventional construction and similar to the room thermostat 90 shown in Figure 3.

, The operationof the modification illustrated in Figures 4 to 7 is substantially the samevas the modiflcationsownin Figures 1, 2 and 3. The motor 81, which represents any form of comb ustion controlling means, is simultaneously under the control .of the two thermostatic elements 104 and 115 and the room thermostat 140. As stated above, the principal function of the thermostat 115 is to raise or lowerthe temperature which the water in the boiler 11 may reach before the boiler thermostat 104 will operateuto cut out the motor 81, and this adjustment is had in accordance with the outside temperature. Thus, as explained above, if the temperature outside falls the operation of the boiler 11 iscontinued s o as to vkeep the water at a. somewhat higher degree of temperature, whereby the temperature in the rooms is maintained substantially constant. On the other hand, if the outside temperature should suddenly increasev the therniostatll will relax a certain amount, thereby allowing the boiler thermostat 104 to interrupt the circuit to the motor 81 before there is any possibility of the rooms becoming overheated and temperature falls by any reason before any useless heating of the water in .the boiler is performed.

- Figure 8 illustrates a slightly modied form of installation as compared with Figures 3 and '7. In Figure 8 the room in parallel with respect to the instrument 99. In this form either instrument 99 or instrument 140 is completely and independently operative to control the motor 81. If, for example, room whatsoever the heater 11 is started regardless of the position of the switch in the instrument 99. Conversely, if both' the temperature of the boiler and the ouside' air fall suicient to tilt the switch' 'tube the circuit to the motor 81 is closed regardless of they temperature of the room at that moment. This latter feature is that the heater 11 will be started in response to a lowered temperature even before the temperature in the room'falls at all. Thus, the heating system is prepared in advance for the demands to be put upon it by virtue of the sudden drop in temperature. Otherwise, the heater 11 would be held out -of operation until the room cooled loil? suiciently to cause the room thermostat 140 to close the circuit. In the form shown in Figure 8 this delay will not be experienced, the heating system l1 being placed entirely under the control of the outside gtemperature,` the boiler thermostat 104 acting as a limit switch to interrupt the circuit when the water in the boiler becomes too high and the room thermostat 140- serving as a second llimit switch to prevent the room temperature from dropping too far in the event that the instrument 99does not close the circuit for any reason.

In all of the modificationsl described above,

the outside thermostat was arranged in cooperation .with the boiler thermostat. Figures 9 and 10 illustrates a construction in which the outside thermostat is arranged to cooperate with the room thermostat. This provides an extremely simple and inexpensive instrument yet one which performs its controllingl operations with practicallyall of the sensitiveness of the instruments previously set forth. In Figures 9 and 10 the reference numeral illustrates a combined room thermostat and weather or outside air thermostat. The room thermostat proper comprises a casing 151 adapted to be secured to a Wall or the like and a second housing or casing 152 is operatively mounted on or adjacent to the casing 151. The casing 152 comprises a suitable stamping formed to t against the casing 151 and secured thereto in any manner desired, as by riveting, welding, screws or the like. The room thermostat coil 154 is disposed within the casing 151, one end thereof being anchored, as at 155, to a movable adjusting hand 156 in the usual manner while the other end of the coil 154 is fastened to a switch shaft 157 journaled in the casings 151 and 152. The shaft 157 carries any suitable form of contactor switch tube 158 and is adapted to contain a switch liquid which is operative to open and close the circuit between a pair of contacts (not shown) carried within the tube l158.

The shaft 157 extends a short distance into the second casing or housing 152 and this end of the shaft has secured to it acollar 160 provided .With an arm 161. The casing 151 on its exterior carries a vcold air or weather thermostat 163 one end of which bears against the arm 161 while the otherv end is suitably anchored in a -post or rivet 165 carriedl by the casing 151. The

thermostat 140 is arranged .n

especially important in.

ings 17' and 101 in the previously described,

modifications. A cold air conduit Aleads from outside the building into the interior of the casing 152, and as best shown in Figures 10 and4 11, one -end of the casing 170 projecting a substantial distancev into the lower portion of the casing 152, This end of the conduit 170 is provided with a manually adjustable butter-fly valve 173 which, in connection with the second adiustable valve later to be described, serves tocontrol the amount of cold air admitted through the cold air duct 170. The casing 152 is provided with a suitable hooded'outlet 175 and this outlet is provided with a second butterfly valve 176 whichis capable of manual adjustment.

'I'he outlet 175 opens downwardly andin order i to preventl trapping a small quantity of heated air in the upper portion of the casing v152 which might interfere with the normal circulation of coldAair in through the conduit 170, the upper portion of the casing 152 is provided with one i more vents 178 acting to permit the escape of any heated air which might otherwise become trapped. Adjustment of the valves 173 and 176 serves to control the amount .of cold air flowing in through the conduit 170. Y

The contacts disposed within the contact tube 158 are operatively connected with a conductor 180 leading to the Aline switch 85 and a conductor 181 leading to one side of the motor 81. The other side of the motor 81 is directly connected through al conductor 182 to the other side of the line switch 85.A

In operation, the thermal element 154 issubjected to room temperature and the thermal 'element 163 is subjected to the temperature of the outside air. These two thermal elements are arranged in a manner similar to the associated pairs of thermal elements previously described. For example, if there is a drop in temperature the thermal relement 163 will be relaxed so that element 154 will have suflicient force to'close the circuit through the contacts in the tube 158. This will start the operation `oi' the boiler 11 which will continue until the temperature of the room has been raised sulficiently high so that thethermal element 154 will be biased sufl'iciently to tilt the tube 158 against the power of the thermal element 163, the latter varying, of course, in accordance with the temperature of the outside air., -v

This form of control has one feature which may be advantageous under many conditions. When the outside airv temperature falls, the temperature at which the mercury switch tube 158 will be tilted to open the motor. circuit is raised so that, in effect, the room temperature must be brought to a somewhat higher degree before the boiler 11 is shut down than would be the case if the air temperature were higher. 'Ihe effect of. this arrangement is three-fold. In the first place, the falling temperature will start the heater even before the room has cooled to the usual operating temperature, thus preventing the time lag generally lpresent where with the temperature falling the heater is not started until the room has cooled, which requires an appreciable length of time. In the second place, the heater, after it has started,

`will be kept in operation longer, thereby insuring that the rooms will be kept up to the proper temperature even though the outside temperature is falling rapidly, and in the third place, the room temperature tends to be held at somewhati a higher level than would otherwise be the case in order to take care of increased' radiation and the like because of the increase in temperature difference between the inside and the out'- side. While in this form I have not shown any boiler thermostat it is to be. understood, of course, that such an instrument may be provided if desired, and the` instrument may be arranged either in series or parallel with the room thermostat .150. It is also possible to` utilize in the construction shown in Figure 11 an instrument such as the ones shown in Figures 1 and 2, and Figures 4 to 6, in which case it would be'possible to arrange this instrument either in series or parallel with the instrument 150 shown in Figure 11.

`It is also to be understood that while I have shown the pairs of associated thermostats as disposedv in mutually opposing relation,l and acting upon the same switch shaft, other arrangements are possible in order to secure the combined controlling effect of thetwo temperature conditions. For example, such thermostats may be serially arranged, so that a true cumulative elect is secured which is not modied by any variations in the respective resiliency of these elements.v As a practical matter, however, the

constructions illustrated secure exactly thisre- .different means may be employed in the practice of my invention. For example, I have shown the electrical leads as directly connected to the motor 81. Obviously, of course, these leads may connect to a relay or relays, depending upon what boiler equipment and the like it is desired to employ. Further, it is also to be understood that where I have shown means relying on induced circulation for bringing in cold or outside air, vother means such as fans and the like may be employed where such in'- duced Acirculation might not prove completely satisfactory.

'I'he structures specifically described above all relate to heating means. The principles of the present invention are, however, equally applicable to cooling means, such as refrigeration systems and the like. In other words, a refrigerator is merely thev reverse of a heater, and both .heating and cooling devices are generically similar in that each sets up a zone having a temperature different than the temperature of the sur.. rounding zone, the effect of the latter being to continually tend to bring the temperature of the treated zone to substantially the same temperature' as that of the surrounding zone. Therefore, variations in the temperature of the Vsurrounding zone or space affect the temperature .Within the treated zone in about the same manner, whether the treated zone be a heated space or a cooled'space. Further, the principles of the present invention are also equally applicable to characteristics existing in two or more correlative zones. For purposes of illustration, all of these are represented by the heating system described above and the cooling system now to be described.

Figures 12 to 16 are illustrative of the application of the present invention to a refrigeration system and in thesel figures the reference numeral 200 indicates a refrigerator of the type adapted particularly for domestic use. Such refrigerators usually include a motor or other source of power 201 operating a compressor 202 which serves to compress the refrigerating liquid contained within the system, the expansion of which liquid occurring in cooling coils 203 serving to maintain the lowered temperature within the refrigerator 200. Usually, some form of thermostatic means or the equivalent is utilized for controlling the operation of the motor or other source of energy 201. Such thermostatic means is commonly arranged to start the operation of the motor 201 and the compressor 202 toI lower the temperature within the refrigerator 200 whenever the temperature therein rises to a certain point. Frequently such means takes the form of pressure bellows responsive to the vapor pressure in the refrigerant circuit, which pressure is approximately proportional to the inside temperature. Thermostats may also be ernployed. When the motor 201 has been operated a time sufcient to lower the temperature within the refrigerator 200 to a certain point, the thermostatic means operates to shut ci! the motor 201. Usually the motor 201 is operated by electric power and the starting and stopping thereof may be conveniently controlled by the operation of known forms of switching means.

In order that the motor 201 shall not be continually starting and stopping the temperature control means is usually so arranged that the temperature within the refrigerator 200 varies over a considerable range, the smaller the range, of course, the greater the number of starts and stops necessary for the compressor system to make. For example, the refrigerator may be arranged to start whenever the temperature within the refrigerator box reaches 50 degrees F. and to stop whenever the temperature reaches 32 degrees F., the whole purpose being to provide such arrangement that the compressor system will be either operating for a material length of time or idle a material length of time. If the temperature of the cooling unit is the determining factor the temperature range will be much lower. v

The length of time which is required for the temperature of the refrigerator box to rise from, say 32 degrees to 50 degrees, during which time the motor 201 is idle, varies with the outside temperatures, that is, it varies with the temperature of the air surrounding the refrigerator box 200. If,for example, the temperature of the room Aor other space in which the box 200 is `positioned is relatively low it wouldbe unneces- .sary to run the temperature of the refrigerator down to, say, 40 degrees F. On the other hand, if the temperature surrounding the refrigerator box 200 is relatively high it might be necessary for best and most efficient operation to operate' ,tions In Figure 12 the refrigerator thermostat is indicated'by the reference numeral 210. Ordinarily this thermostat operates a switch or a relay capable of controlling the circuit to the motor 201. According to the principles of the present invention, I provide an auxiliary thermostat 211 mounted exteriorly of the refrigerator box 200, as by a bracket means 212 or the like. This auxiliary thermostat is substantially identical for all practical purposes with the form Aof thermostat shown in Figures 4 and 5. The thermal responsive element thereof is indicated by` the reference numeral 215 and one end of the element is anchored to the casing of the thermostat while the other end thereof is secured to a shaft 216 in substantially the same manner as described above in connection with Figures 4 and 5. The shaft 216 atV its outer end carries the mercury switch tube 218 which controls the operation of the motor 201. At its inner end the shaft 216, which extends through the walls of the refrigerator box, is connected to be acted upon by the refrigerator thermostat 210. This latter thermostat, as will be clear from Figure 12, is disposed withln'or adjacent to the cooling coils 203 and is subjected to the temperature thereof while the thermal element 215 is subjected to Vthe temperature of the outside air. The refrigerator thermostat 210 may, as pointed out above, be in the form of means responsive to the pressure of the refrigerant in the compressor system, but since the operation of each is substantially the same the thermostat 210 will be considered representative of each or the equivalent thereof.

The thermostats 210 and 215 are arranged in series, thatis, they are both so connected to the shaft 216 that the rotation thereof due to a rise in temperature of one of the thermostats is assisted lby the operation of the other thermostat when it is likewise subjected to an increase'in temperature, and is opposed by the other thermostat if the latter is subjected to a decrease in temperature. Thus, if the outside temperature is high the motor 201 will be started in operation sooner than it would be if the outside temperature is low, and will be continued in operation longer. This provides for automatic operation of the refrigerator which adjusts the same automatically for the particular conditions under which it is operating.

Figure 15 shows the circuit usually employed when the thermostats 210 and 215 are interconnected by means of a shaft, such as 216.

Figure 14 is illustrativeof a second form of auxiliary thermostat in which the refrigerator thermostat and the auxiliary thermostat are not mechanically connected together by means of a shaft but are entirely 4separate and independent of each other. In this form the shaft 216 is entirely omitted, the auxiliary thermostat 215 being secured to the outside of the refrigerator at any place thereon. Where the shaft 216 is not employed the refrigerator thermostat 210 is equipped with some form of electric switch, such as a mercury switch tube 220. This is in addition .to the switch tube 218 which forms a part of the thermostat 215. In this form the two switches are arranged in series in the circuit of the motor 201, as best shown in Figure 16. Here the opration of the auxiliary thermostat 215 is simply to cut in and cut outfaccording to the temperature outside the refrigerator box. That is, when the outside temperature is cold enough so that the operation'of the motor 201 may be dispensed with entirely, as in the winter time, the circuit to the motor 201 is permanently. interrupted until the outside temperature rises suillciently to warrant the operation ofthe refrigerator. At the present time, during cold weather or in the winter time the refrigerator is frequently turned oif altogether by manually opening the circuit to the motor 201, but when warmer weather arrives it is' necessary for the owner to close the circuit so that the refrigerator may be operated. This is not the best operation for sometimes a warm day suddenly appears and the food within the refrigerator 200 may spoil unless the owner anticipates the change in weather. By virtue of the auxiliary thermostat 215, as shown in Figures 14 and 16, the owner need pay no attention whatsoever to the change of weather, the thermostat 215 serving itself to anticipate change in weather and interrupt or restore the refrigerator 200 to operative condition according to the outside temperature.

It will be observed that the. auxiliary thermostat 215 is subjected only to the temperature of the room in which the refrigerator is placed. As to the space within the refrigerator, the auxiliary thermostat 215 stands in the same relation as the auxiliary thermostats 35 and 163 with respect to the temperature within the house. Obviously, of course, the auxiliary thermostat 215 could, if desired, be equipped with conduits leading cold air from outside the house thereto.

In its broader aspects, the present invention is not to be limited necessarily to temperature responsive means. By that is meant that the present invention contemplates broadly the provision of means responsive to a given characteristic to automatically control means modifying that characteristic in accordance with or in anticipation of the extent or character of additional factors also present and which also tend to modify that characteristic. Instead of temperature, for example, humidifying means may be mentioned, in which case instead of thermostatsv responsive to temperature, means responsive to humidity would be employed.

It will be understood, therefore, that while I have described the preferred structural embodiment of the present invention, my invention is not to be limited tothe specific means shown and described but that, in fact, widely different means may be employed in the broader aspects of my invention.

What I claim, therefore, and desire to secure by Letters Patent is:-

1. Switch mechanism for controlling refrigerators and the like having an electrically driven unit and circuit meansv associated therewith, said mechanism comprising shiftable contact means for opening and closing said circuit means, a member for shifting said contact means, a thermal element responsive to the temperature of the air outside the refrigerator and connected with said member to shift the contact means to open said circuit means when the temperature Aoutside the refrigerator is relatively low and to close said circuit means when the temperature outside the refrigerator is relatively high, and a second thermal element responsive to the temperature inside the refrigerator and also connected with said member for shifting the contact means to op'en and close 'said circuit means in response to temperature conditions inside the refrigerator only when the temperature outside the refrigerator is relatively high.

2. Control means for heating systems and the like comprising, in combination, a casing, a.

shaft journaled for rocking movement therein,

shiftable contact means including parts carried by said shaft, a pair of separated thermal elements, each anchored at one end and having its other end operatively associated with said shaft whereby said shiftable contact means is simultaneously under the control of two independent thermal elements, and means subjecting said separated thermal elements to room temperature and outside temperature, respectively.

3. Control means for heating systems and the like comprising, in combination, a casing, a shaft journaled therein, a mercury switch tube carried by said shaft, a thermostatic element anchored at one end to said casing and con-.

nected at its other end to said shaft, a second casing secured to said first casing, a second thermostatic element anchored at one end within said second casing and having its other end connectedJwith said shaft, and means subjecting one of said thermostatic elements to outside temperatures.

4. Control means for heating systems and the like comprising.. in combination, a casing, a shaft journaled therein, a mercury switch tube carried by said shaft, a thermostatic element anchored at one end to said casing and connected at its other end to said shaft, a second casing secured to said first casing, a second thermostatic element anchored at one end within said second casing and having its other end connected with said shaft, and means for circulating through said second casing a stream of fluid in thermal contact with said second thermostatic element.

5. Control means for heating systems and the like comprising, in combination, a casing, a shaft journaled therein, a mercury switch tube carried by said shaft, a thermostatic element anchored at one end to said casing and connected at its other end to said shaft, a second casing secured to said first casing, a second thermostatic element anchored at one end With- Vin said second casing and having its other end connected with said shaft, means for circulating through said second casing a stream of fluid in thermal contact with said second thermostatic element, and shiftable valve means for controlling the amount of fluid directed through said second casing.

6. Control means for-heating systems and the like comprising, in combination, a vented casing, a thermostatic coil having one end anchored therein, a shaft rotatably supported within said casing and operatively connected with the other end of said thermostatic coil, a liquid contactor switch carried by said shaft and actuable by said thermostatic coil, said shaft extending outwardly of said casing, a second thermostatic element, means mounting said element on the exterior of said casing with one end anchored thereto and the other end operatively connected with said shaft, a housing attached to said casing and surrounding said thermostatic element, and conduit means for directing fluid into and through said housing in thermal relation with said thermostatic element.

7. Control means for thermal systems and the like embodying separated zones normally at different temperatures and including means for modifying at least one of said zones, said means comprising, in combination, a casing, a rotatable shaft having at least a portion journaled in said casing, a pair of thermostatic elements operatively associated with said shaft, acontactar switch carried by said shaft and under the cumulative control of said thermostatic. elements, conduit means for directing a flow offluidfrom one of said zones into and through said casing, an outlet to permit said fluid to escape from said casing, and adjustable-valve means for controlling the flow of fluid through said outlet.

8. In a system embodying temperature modifying means adapted to maintain a temperature diiference betweentwo zones in which the temperature of one .zone is affected by the temperature of the other, regulating means comprising a first casing, a second casing, a shaft journaled in said casings, a thermal element disposed in the rst casing and having one end anchored thereto and the other end secured to the adjacent end of the shaft, a second thermal element disposed in and having one end anchored to said second casing, the other end o'f said element being secured to the other end of said shaft, and switch means actuated by said shaft and controlled byboth of said thermal elements.

HERBERT E. BUCKLEN.

CERTIFICATE OF CORRECTION.

Patent No. 1,991,016. February 12, 1935.

HERBERT E. BUCKLEN.

It is hereby certified thaterror appears in the printed specification of the above numbered patent requiring correction as follows: Page 7, second column, line 55, claim 6, for "heating" read thermal; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 19th day of March, A. D. 1935.

Leslie Frazer (Seal) Acting Commissioner of Patents.

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