US3665363A

US3665363A - Thermostatic control device and system utilizing the same

Info

Publication number: US3665363A
Application number: US79122A
Authority: US
Inventors: David M Rosenberg; Siegfried E Manecke
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1970-10-08
Filing date: 1970-10-08
Publication date: 1972-05-23
Anticipated expiration: 1989-05-23
Also published as: FR2111127A5; NL7113760A; DE2150109A1; IT938995B; SE371715B; CA952166A; AU3431971A; GB1344910A

Abstract

Electrical switch means carried by frame means. A U-shaped bimetal member defining a pair of legs interconnected at adjacent ends thereof by an elbow portion pivotally mounted to the frame means. A plunger means is movably carried by the frame means and is disposed between one of the legs of the bimetal member and the switch means to operate the switch means in relation to the position of the one leg relative to the frame means. Cam means is movably carried by the frame means and acts on the other leg of the bimetal member to adjust the pivotal position of the bimetal member and, thus, the temperature setting that the thermostatic device will open the switch means, the cam means being movable across the longitudinal axis of the other leg of the bimetal member to adjust the same.

Description

Unite States Patent Rosenberg et alg 51 May 23, 1972 THERMOSTATIC comm. DEVICE AND SYSTEM UTILIZING THE SAME Primary Examiner-Volodymyr Y. Mayewsky Assistant Examiner-F. E. Bell Attorney-Auzville Jackson, In, Robert L. Marben and Can- [72] Inventors: David M. Rosenberg; Siegfried E. dor. Candor 8:. Tassone Manedte, both of Indiana, Pa. [57] ABSTRACT [73] Assignee: Robertshaw Conn-ob Company, I

Ri h d v Electrical suntch means earned by frame means. A U-shaped bimetal member defining a pair of legs interconnected at ad- [221 Med: Oct jacent ends thereof by an elbow portion pivotally mounted to [2!] Appl No; 79,122 the frame means. plunger means is movably carried by the frame means and IS disposed between one of the legs of the bimetal member and the switch means to operate the switch [52] US. 353 means in relation to the position of the one leg relative to the [5 Ill- 37/12 frame means. Cam means is movably carried by the frame l l, 347, 349, means and acts on [he othe leg of [ha member to ad- 379 just the pivotal position of the bimetal member and, thus, the temperature setting that the thermostatic device will open the [56] References Cited switch means, the cam means being movable across the longitudinal axis of the other leg of the bimetal member to adjust UNITED STATES PATENTS the same 2,493,294 l/l950 Kronmiller ....337/347 2,786,917' 3/1957 Casey ..337/1 11 Cm WWW FOREIGN PATENTS OR APPLICATIONS 565,252 11/ 1944 Great Britain ..337/360 91 23 39 J58 I 96" 59 28- s6 76 5 45 86-- 2 48 27 47 88- 40 4- 7s- 73 I 49 74 63 77' 6O 56 l I J 8' 79 85 22 8O 35 a4 Patented May 23, 1972 3,665,363

4 Sheets-$118913 1 3 INVENTORS DAVID M. ROSENBERG SIEGFRiED E. MANECKE BY W,M;W

THEIR ATTORNEYS Patented May 23, 1972 3,665,363

4 Sheets-Sheet 2 30 86 3o 27 27 28 88 78 FIGS 47* 51 e2 FIG.6

INVENTORS ID M. SENBERG GFRl E. MANECKE 2 V BY j FA ZW M;%

TH EIR ATTORN EYS Patented May'23, 1972 3,665,363

4 Sheets-Sheet 5 FIG. 8

INVENTORS DAVID M. ROSENBERG BY SIEGFRIED E. MANECKE 1 64A 63A 65A ET 3 a I g r THEIR ATTORNEYS Patented May 23, 1972 3,665,363

4 Sheets-Sheet 4 INVE O DAVID M. ROSE E SIEGFRIED EMANECKE THEIR ATTOR NEYS THERMOSTATIC CONTROL DEVICE AND SYSTEM UTILIZING THE SAME This invention relates to an improved thermostatic control device as well as to an improved system utilizing such a control device or the like.

It is well known that thermostatic devices have been provided for controlling heating means and the like that is disposedremote from the thermostatic device, the thermostatic device sensing room temperature and causing the heating means for the room or the like to turn on when the temperature of the room falls below a selected temperature as well as causing the heating means to turn off when the room temperature exceeds the selected temperature. Such thermostatic device has an auxiliary heater therein which only operates when the heating means is in its on condition to raise the temperatureat the thermostat to cause the thermostat to turn off the heating means before the temperature in the room exceeds the selected temperature so as to prevent an adverse overshoot situation and thereby provide a narrow temperature difierential in the room or rooms being maintained by such thermostatic means.

Accordingly,-it is a feature of this invention to provide an improved thermostatic device of the above type.

In particular, one embodiment of this invention provides a frame means'carrying electrical switch means. A U-shaped bimetal member that defines a pair of legs interconnected together at adjacent ends thereof by an elbow portion is pivotally mounted by the elbow portion thereof to the frame means. A movable plunger is carried by the framemeans and is disposed between one of the legs of the bimetal member and the switch means to operate the switch means in relation to the position of the one leg relative to the frame means. Cam means is movably carried by the frame means and acts on the other leg of the bimetal member to adjust the pivotal position of the bimetal member and, thus, the temperaturesetting that the thermostatic device will open the switch meansthe cam means being movable across the longitudinal axis of the other leg of the bimetal member ,to adjust the same.

Accordingly, it is an object of this invention to provide an improved thermostatic device having one or moreof the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved control system utilizing such a thermostatic device.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein: I a

FIG. 1 is a front view of one embodiment of the thermo static device of this invention.

FIG. 2 is an enlarged view of the thermostatic device of FIG. 1 with the cover member thereof removed.

FIG. 3 is a reduced fragmentary view of the thermostatic device of FIG. 2 with the selector means and another cover plate thereof removed to illustrate the electrical switch means and terminal means therefor.

FIG. 4 is an enlarged cross-sectional view taken on line 4-4 of FIG. 1. I

FIG. 5 is a cross-sectional view-taken on line 5-5 of FIG. 2.

FIG. 6 is a fragmentary rear view of the thermostatic device of FIG. 2.

FIG. 7 is an exploded perspective view of certain of the parts of the thermostatic device of FIG. 1.

FIG. 8 is a view similar to FIG. 3 and illustrates another thermostatic device of this invention.

FIG. 9 is a view similar to FIG. 4 and illustrates the thermostatic device of FIG. 8.

FIG. 10 is a fragmentary rear device of FIG. 8.

While the various features of this invention are hereinafter view of the thermostatic described and illustrated as being particularly adapted to provide thermostatic control of a heating means for the rooms of a building or the like, it is to be understood that the thermostatic device of this invention can be utilized for controlling other devices as desired. 1

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Refen'ing now to FIGS. 1-7, the improved thermostatic device of this invention is generally indicated by the reference numeral 20 and comprises a frame means 21 defined by a housing member 22 having a recess23 therein receiving an electrical switch means 24 in a manner hereinafter described and being closed by a removable cover plate 26. The frame means 21 includes a bracket plate 27 secured to the housing member 22 in any suitable manner so as to pivotally carry a selector means 28 pivotally mounted thereto by rivet means 29, the plate 27 having depending L-shaped legs 30 riveted to the housing member 22 so that the cover plate 27 is disposed in spaced relation relative to the previously described cover plate 26.

A cover plate 31 is adapted to be disposed against and be secured to the housing member 22 in any suitable manner to cover the plate 27 as illustrated in FIG. 4, the cover means 31 having a slot 32 at one end thereof and through which an outwardly directed tang 33 of the selector means 28 can project so as to be manually grasped to move the selector means 28 relative to the frame means 21 while at the same time indicating a temperature setting as provided by suitable scale means 34 provided on the housing member 22 as illustrated in FIG. 1.

If desired, a suitable temperature indicating thermometer means 35can be carried by the cover means 31 and have an indicating pointer means 36 viewable in a window means 37 cut in the cover member 31 as illustrated in FIG. 1.

The electrical switch means 24 comprises a snap blade 38 having opposed

ends

39 and 40 while being medially slotted to define three

legs

41, 42 and 43 with the outboard legs 42 and 43 being crimped at 44 to render the blade 38 snap acting in a manner fully disclosed and claimed in applicants [15. Pat. No. 3,238,337. A leaf spring 45 is secured to the end 40 of the blade 38 as well as to the middle leg 41 by fastening means 46 so as to bear against a set screw 47 threadedly disposed in a threaded bore 48 in an end wall 49 of the housing means 22, the end 40 of the blade 38 being secured to a terminal plate 50 carried by the housing means 22in the chamber 23 thereof and interconnected to an external terminal means 51 by an interconnecting cylindrical rivet means 52 whereby the external terminal 51 is electrically interconnected to the snap blade 38.

The other end 39 of the snap blade 38 carries contact means 53 adapted to cooperate with a fixed contact means 54 carried by a terminal plate 55 secured to the housing means 22 by a cylindrical rivet means 56 that electrically interconnects the plate 55 to external terminal means 57. The free end 39 of the snap blade 38 is adapted to snap between the fixed contact 54 and a set screw 58 threadedly carried in a threaded bore 59 in the end wall 49 of the housing means 22 except that the snap blade 38 has a natural tendency to always return its contact 53 against the fixed contact 54 as will be apparent hereinafter.

Another terminal plate 60 is disposed in the recess or cavity 23 of the housing means 22 and is secured thereto by cylindrical rivet means 61 that electrically interconnects the plate 60 to an external terminal means 62. An electrical resistance 63 has one of its leads 64 electrically interconnected to the plate 60 while the other terminal lead 65 thereof is electrically interconnected to the plate 50.

In this manner, a power source lead 66 from a power source 67 is adapted to be electrically interconnected to the plate 60 at the terminal 62 while the other power source lead 68 is adapted to be interconnected to the plate 55 at the terminal 57. One end 69 of the means 70 that controls a heating means, whether the means 70 is the heating means itself or control means for a heat exchanger or the like, is electrically interconnected to plate 50 at the terminal 51 by lead 71. The other end of the means 70 is interconnected by a lead 72 to the terminal 62 that leads to the terminal plate 60 as fully illustrated in FIG. 3.

Upon closure of contact 53 with contact 54 a current path from one side of power source 67 through heating means 70 to the other side of power source 67 is established. The current path includes lead 68 connected to one side of power source 67, terminal 57, plate 55, contact 54, contact 53, snap blade 38, plate 50, terminal 51, lead 71, heating means 70, lead 72 connected to terminal 62 of plate 60 and continues via lead 66 to the other side of power source 67. Since the electrical resistance 63 is connected between

plates

50 and 60 it is in parallel with the heating means 70 and is therefore energized when heating means 70 is energized.

The cover member 26 that closes the open end of the chamber 23 includes an arcuate portion 73 that provides a recess means 74 for retaining the resistor 63 therein as fully illustrated in FIG. 4. In addition, the cover member 26 has bores 75 and 76 passing therethrough for a purpose hereinafter described.

A U-shaped bimetal member 77 is provided and defines two

parallel legs

78 and 79 interconnected together at adjacent ends thereof to a U-shaped elbow portion 80 that is adapted to be disposed around a pivot pin 81 carried within suitable apertures 82 of opposed cars 83 of the bracket member 27 as illustrated in FIG. 4. The bracket member 27 has a pair of depending tan'gs 84 at one end 85 thereof that holds the elbow 80 against the pi'votshaft 81 in the manner fully illustrated in FIG. 4.so that the bimetal member 77 will pivot about the shaft 81'and, thus, about the frame means 21.

The leg 78 of the bimetal member has a tang 86 depending from the free end 87 thereof to be engaged by an arcuate cam track 88 on the selector means 28 which is adapted to be A pivoted on the bracket means 27 so that the cam track 88 will move across the longitudinal axis of the leg 78 and bear against the end tang 86 thereof so as to adjust the pivotal position of the bimetal member 77 relative to the frame means 21 and, thus, determine the temperature setting of the thermostatic device 20 as will be apparent hereinafter.

' The other leg 79 of the bimetal member 77 has an internally threaded opening 89 passing through the free end 90 thereof and threadedly receiving an adjusting screw 91 which is alignable with the bore 75 in the cover member 26 when the bimetal member 77 is assembled to the bracket means 27 as illustrated in FIG. 4.

An insulating rod or pin 92 is disposed in the bore 75 of the cover member 26 so that the opposed ends 93 and 94 of the pin 92 can respectively engage the end 95 of the set screw 91 and the free end 39 of the snap blade 38 of the electrical switch means 24.

The selector means 28 has an outwardly directed and arcuately bent'tang 96 alignable with the other end 97 of the set screw 91 for a purpose hereinafter described.

The operation of the thermostatic device 20 of this inventionas utilized in the control system of this invention, which is generally indicated by the reference numeral 98 in FIG. 3, will now be described.

The operator or the like positions the end 33 of the selector means 28 relative to the scale 34 for a desired temperature setting so that the thermostatic device 20 will tend to maintain the temperature in the room containing such thermostat 20 at the set temperature because thethermostat 20 will operate the heating means 70 when the temperature sensed in the room is below such setting of the end 33 of the selector means 28.

In particular, as long as the temperature in the room is above the temperature setting of the end 33 of the selector means 28, the cam track 88 has pivotally positioned the bimetal member 77 in such a manner that the leg 79 thereof has its free end 90 in such a position that leg 79 of the bimetal member 77 through the plunger or pin 92 acts against the end 39 of the snap blade 38 to overcome the natural bias of the snap blade 38 and maintain the snap blade 38 against the set screw 58 whereby no' current is adapted to flow between the spaced

contacts

54 and 53 and, thus, no current is permitted to flow through the heating means 70 nor through resistance 63 connected in parallel across heating means 70.

However, when the temperature in the room falls below the selected temperature setting of the thermostat 20, the leg 79 of the bimetal member 77 has warped to the left in FIG. 4 a distance sufiicient to cause the snap blade 38 to move its contact 53 against the fixed contact 54 and, thus, complete the circuit through the heating means 70 to heat up the room carrying the thermostat 20. However, at this time, current is also flowing through the resistor 63 which begins to heat up adjacent the bimetal member 77 to cause the same to again open the contacts 53 and 54 a short time before the room would reach such temperature should the heating means 70 continue to operate so as to prevent adverse temperature overshooting condition. 7

Thus, it can be seen that the bimetal leg 79 by warping back and forth in response to temperature change will tend to maintain the temperature of the room at the temperature set by the selector means 28.

Ifdesired, movement of the end 33 of the selector means 28 completely to the left in FIG. 1 can cause the tang 96 thereof to bear against the end 97 of the set screw 91 in such a manner that the same will positively force the plunger means 92 and free end 39 of the snap blade 38 away from the fixed contact 54 and, thus, against the set screw 58 so as to maintain a positive ofi condition of the thermostat 20. However, if such a positive off of the thermostat 20 is not desired for the snap blade means 38 thereof, the tang 96 can be bent to be coplanar with the remainder of the selector means 28 so that the same will not act on the end 97 of the set screw 91 so that no positive 013' condition will be provided by the selector means 28.

Should it be desired to provide a positive foff position of the control system 98 when the selector means 28 is moved to an ofF position thereof, a second electrical switch means can be provided for the thermostat 20. The second electrical switch is connected to open one side of the power source with switch means 24 connected to open and close the other side of the power source. Upon moving selector means 28 to the off position at least one side of the power source will be broken regardless of the position of the switch means 24.

In particular, reference is now made to FIGS. 8, 9 and 10 wherein another thermostatic device of this invention is generally indicated by the reference numeral 20A and parts thereof identical to the thermostat 20 previously described are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIGQ9, the thermostat device 20A is substantially identical to the thermostat device 20 previously described except that another switch means 99 is disposed in the chamber 23A and comprises'a switch blade 100 having one end 10] thereof secured to the housing means 22A bya cylindrical rivet 102, FIG. 8, that is electrically interconnected to an external tenninal means 62A. The switch blade 100 is electrically interconnected to the switch blade 38 by the resistor means 63A having one of its leads 64A interconnected to the switch blade 100 while the other lead 65A thereof is interconnected to the plate 50A that is electrically interconnected to the snap blade 38A. The other end 103 of the switch blade 100 can'ies a contact means 104 which is normally disposed in electrical contact with a fixed contact 105 carried by a contact blade 106 secured to the housing means 22A and being interconnected by a cylindrical rivet 107 to an external terminal means 108 that is adapted to-be interconnected to one side of the power source 67A of FIG. 8 by a lead 66A. The other side of power source 67A is interconnected to the fixed contact 54A of the snap switch 24A in the manner previously described. The heating means 70A is connected via leads 71A and 72A to terminals 51A and 62A respectively.

Thus,in order for the heating means 70A to be operated by the power source 67A, the switch means 99 must be in a closed position as well as the switch means 24A.

Another insulating rod or pin 109 is disposed in the bore I 76A of the cover member 26A and has one opposed end 110 adapted to bear against switch blade 100 and the other op posed end 111 adapted to be alignable with another arcuate tang means 1 12 of the selector means 28A.

In this manner, only when the selector means 28A of the thermostat A shown in FIG. 9 is moved completely to the left as viewed in FIG. 8 will the tank 112 of the selector means 28A act against the end 111 of the plunger means 109 sufficiently to cause the plunger means 109 to move the switch blade 100 tothe right in FIG. 9 a distance sufiicient to open the

contacts

104 and 105 so that no electrical current can flow through the heating means 70A until the selector means 28A shownin FIG. 9 is again moved to the right as viewed in FIG. 8 to pennit the switch means 99 to close. If desired, the other tang 96A of the selector means 28A can also cause positive opening of the switch means 24A in the manner previously described for the thermostat 20 at the same time the switch means 99 is being positively maintained in an open position thereof to provide a double pole thermostat.

Therefore, it can be seen that an improved thermostatic ,deviceis provided by this invention as well as an improved control system utilizing such a thermostatic device. While the form of theinvention now preferred has been disclosed as required by the patent statutes, other forms may be utilized, all coming within the scope of the claims which follow.

What is claimed is:

1. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to-the position of said one leg relative to said frame means, and cam means movably carried by said .frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic devicewill open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same.

2. A thermostatic device as set forth in claim 1 wherein said cam means comprises part of a manual selector means for said device.

, 3. A thermostatic device as set forth in claim 2 wherein said .manual selector means has means for operatively engaging against said one leg of said bimetal member to directly move said one leg and said plunger means to a position that opens said switch means.

4. A thermostatic device as set forth in claim 3 wherein said means for operatively engaging against said one leg of said bimetal member comprises another cam means.

5. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means,

plunger means movably carried by said frame means and pivotally mounting said bimetal member to said frame means,

plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation tothe position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to ad just the same, said cam means comprising part of a manual selector means for said device, said selector means having a tang that is to be manually grasped to move said selector means, said tang providing temperature setting and indicating means for said device.

8. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and'cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member, and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said one leg of said bimetal member carrying an adjusting member having one end engaging said plunger means. g

9. A thermostatic device as set forth in claim 8 wherein said adjusting member is disposed at the free end of said one leg of said bimetal member.

10. A thermostatic device as set forth in claim 9 wherein said manual selector means has means for engaging against the being disposed between one of said legs of said bimetal j member and said switch means to operate said switch means selector means for said device, said manual selector means.

having means for operatively engaging against said one leg of said bimetal member to directly move said one leg and said plunger means to a position that opens said switch means, said means for operatively engaging against said one leg of said bimetal member comprises another cam means, said other cam means comprising an arcuately disposed cam tang of said selector means.

other end of said adjusting member to directly move said one leg and said plunger means to a position that opens said switch means.

11. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion.

pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and i being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, and another electrical switch means carried by said frame means, said other switch means with said first mentioned switch means permitting said thermostatic device to be connected for double pole operation.

12. A thermostatic device as set forth in claim 11 wherein said cam means comprises part of a manual selector means for said device, said frame means carrying another movable plunger means for operating said other switch means, said selector means having means for engaging and moving said other plunger means to open said other switch means.

13. A thermostatic device as set forth in claim 12 wherein said means for engaging said-other plunger means comprises another cam means carried by said selector means.

14. A thermostatic device as set forth in claim 13 wherein said other cam means comprises an arcuately disposed cam tang of said selector means.

15. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal memberto adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the iongitudinal axis of said other leg of said bimetal member to adjust the same, said frame means carrying a pivot pin and havingtang means disposed adjacent said pivot pin means, said elbow of said bimetal member receiving said pivot pin and being disposed between said tang means and said pivot pin to be pivotally mounted to said frame means.

16. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switchmeans carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said'switch means is open, a U- shaped bimetal member defining a pair of legs-interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and beingdisposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same.

17. In a control system as set forth in claim 16, the further improvement wherein said cam means comprises part of a manual selector means for said device.

18. In a control system as set forth in claim 17, the further improvement wherein said manual selector means has means for operatively engaging against said one leg of said bimetal member to directly move said one leg-and said plunger means to a position that opens said switch means.

19. ln a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source. to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U- shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and saidswitch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said cam means comprising part of a manual selector means for said device, said manual selector means having means for operatively engaging against said one leg of said bimetal member to directly move said one leg and said plunger means to a position that opens said switch means, said means for operatively engaging against said one leg of said bimetal member comprising another cam means.

20. In a control system as setforth in claim 19, the further improvement wherein said other cam means comprises an arcuately disposed cam tang of said selector means.

21. In a control system as set forth in claim 17, the further improvement wherein said cam means comprises a cam track on said selector means.

22. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U- shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means.. plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg'relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal'm'ember. and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other legvof said bimetal member to adjust the same, said cam means comprising part of a manual selector means for said device, said selector means having a tang that is to be manually grasped to move said selector means, said tang providing temperature setting and indicating means for said device. I

23. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, elec trical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame -means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movablycarried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said one leg of said bimetal member carrying an adjusting member having one end engaging said plunger means,

24. In a control system as set forth in claim 23, the further improvement wherein said adjusting member is disposed at directly move said one leg and said plunger means to a position that opens said switch means.

26. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U- shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, and another electrical switch means carried by said frame means, said other switch means being electrically interconnected in series between one side of said source and one end of said electrically operated heating means and said first-named switch means being electrically interconnected in series between the other side of said source and the other end of said electrically operated heating means.

27. In a control system as set forth in claim 26, the further improvement wherein said cam means comprises part of a manual selector means for said device, said frame means carrying another movable plunger means for operating said other switch means, said selector means having means for engaging and moving said other plunger means to open said other switch means.

28. in a control system as set forth in claim 27, the further improvement wherein said means for engaging said other plunger means comprises another cam means carried by said selector means, j

29. In a control system as set forth in claim 28, the further improvement wherein said other cam means comprises an arcuately disposed cam tang of said selector means.

30. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U- shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said frame means carrying a pivot pin and having tang means disposed adjacent said pivot pin means, said elbow of said bimetal member receiving said pivot pin and being disposed between said tang means and said pivot pin to be pivotally mounted to said frame means.

Claims

1. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by sAid frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same.

3. A thermostatic device as set forth in claim 2 wherein said manual selector means has means for operatively engaging against said one leg of said bimetal member to directly move said one leg and said plunger means to a position that opens said switch means.

5. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said cam means comprising part of a manual selector means for said device, said manual selector means having means for operatively engaging against said one leg of said bimetal member to directly move said one leg and said plunger means to a position that opens said switch means, said means for operatively engaging against said one leg of said bimetal member comprises another cam means, said other cam means comprising an arcuately disposed cam tang of said selector means.

6. A thermostatic device as set forth in claim 2 wherein said cam means comprises a cam track on said selector means.

7. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said cam means comprising part of a manual selector means for said device, said selector means having a tang that is to be manually grasped to move said selector means, said tang providing temperature setting and indicating means for said device.

8. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in rElation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member, and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said one leg of said bimetal member carrying an adjusting member having one end engaging said plunger means.

10. A thermostatic device as set forth in claim 9 wherein said manual selector means has means for engaging against the other end of said adjusting member to directly move said one leg and said plunger means to a position that opens said switch means.

11. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, and another electrical switch means carried by said frame means, said other switch means with said first mentioned switch means permitting said thermostatic device to be connected for double pole operation.

13. A thermostatic device as set forth in claim 12 wherein said means for engaging said other plunger means comprises another cam means carried by said selector means.

15. A thermostatic device having a frame means, electrical switch means carried by said frame means, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said frame means carrying a pivot pin and having tang means disposed adjacent said pivot pin means, said elbow of said bimetal member receiving said pivot pin and being disposed between said tang means and said pivot pin to be pivotally mounted to said frame means.

16. In a control system having a source of electrical current and an electrically operated heating means, the improvement Comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same.

18. In a control system as set forth in claim 17, the further improvement wherein said manual selector means has means for operatively engaging against said one leg of said bimetal member to directly move said one leg and said plunger means to a position that opens said switch means.

19. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said cam means comprising part of a manual selector means for said device, said manual selector means having means for operatively engaging against said one leg of said bimetal member to directly move said one leg and said plunger means to a position that opens said switch means, said means for operatively engaging against said one leg of said bimetal member comprising another cam means.

20. In a control system as set forth in claim 19, the further improvement wherein said other cam means comprises an arcuately disposed cam tang of said selector means.

22. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heAting means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said cam means comprising part of a manual selector means for said device, said selector means having a tang that is to be manually grasped to move said selector means, said tang providing temperature setting and indicating means for said device.

23. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said one leg of said bimetal member carrying an adjusting member having one end engaging said plunger means.

24. In a control system as set forth in claim 23, the further improvement wherein said adjusting member is disposed at the free end of said one leg of said bimetal member.

25. In a control system as set forth in claim 24, the further improvement wherein said manual selector means has means for engaging against the other end of said adjusting member to directly move said one leg and said plunger means to a position that opens said switch means.

26. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the Temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, and another electrical switch means carried by said frame means, said other switch means being electrically interconnected in series between one side of said source and one end of said electrically operated heating means and said first-named switch means being electrically interconnected in series between the other side of said source and the other end of said electrically operated heating means.

28. In a control system as set forth in claim 27, the further improvement wherein said means for engaging said other plunger means comprises another cam means carried by said selector means.

30. In a control system having a source of electrical current and an electrically operated heating means, the improvement comprising a thermostatic device having a frame means, electrical switch means carried by said frame means and being electrically interconnected to said source and to said heating means to interconnect said source to said heating means when said switch means is closed and to disconnect said source from said heating means when said switch means is open, a U-shaped bimetal member defining a pair of legs interconnected together at adjacent ends thereof by an elbow portion, said elbow portion pivotally mounting said bimetal member to said frame means, plunger means movably carried by said frame means and being disposed between one of said legs of said bimetal member and said switch means to operate said switch means in relation to the position of said one leg relative to said frame means, and cam means movably carried by said frame means and acting on the other leg of said bimetal member to adjust the pivotal position of said bimetal member to adjust the pivotal position of said bimetal member and, thus, the temperature setting that said thermostatic device will open said switch means, said cam means being movable across the longitudinal axis of said other leg of said bimetal member to adjust the same, said frame means carrying a pivot pin and having tang means disposed adjacent said pivot pin means, said elbow of said bimetal member receiving said pivot pin and being disposed between said tang means and said pivot pin to be pivotally mounted to said frame means.