US3617972A

US3617972A - Fuel control system and parts therefor or the like

Info

Publication number: US3617972A
Application number: US880513A
Authority: US
Inventors: Charles D Branson; Denis G Wolfe
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1969-12-09
Filing date: 1969-12-09
Publication date: 1971-11-02
Anticipated expiration: 1988-11-02

Abstract

An electrical thermostat having a movable selector carried by the housing thereof. A temperature sensing device is carried by the housing and has a movable part facing in one direction. A first spring blade is carried by the housing and has a first contact. A second spring blade is carried by the housing and has a second contact cooperable with the first contact. The second spring blade is normally being urged toward the first contact and engages the movable part of the temperature sensing device to follow movement thereof while the first spring blade is normally being urged toward the second contact. Means are carried by the housing for overriding the first spring blade to tend to move the first contact away from the second contact, the selector having a part facing in the one direction and engaging the overriding means for positioning the overriding means relative to the housing and thus positioning the first contact relative to the second contact whereby the temperature sensing device is adapted to place the contacts in contact with each other when the temperature sensing device senses a temperature effect below a preselected temperature effect setting of the selector and is adapted to move the second contact away from the first contact when the temperature-sensing device senses a temperature effect above the preselected temperature effect of the selector means.

Description

United States Patent [72] Inventors Charles D. Bronson;

Denis G. Wolfe, both of Greensburg, Pa. [21] Appl. No. 880,513 [22] Filed Dec. 9, 1969 [23] H Division of SerfNo. 672,520, Oct. 3, 1967,

Pat. No. 3,521,814 w w 0 [45] Patented N56. 2,1971" m [73] Assignee Robertshaw Controls Company Richmond, Va.

[54] FUEL CONTROL SYSTEM AND PARTS THEREFOR OR THE LIKE 10 Claims, 27 Drawing Figs.

[52] U.S. Cl 337/323, 337/330 [51] Int. Cl ..H01h 37-/26, l-lOlh 37/40 [50] Field of Search 337/44, 87, 309, 311, 323, 330, 340, 363, 364, 375, 383, 397, 400

[56] References Cited UNITED STATES PATENTS 3,469,779 9/1969 Wolfe et al. 337/323 X 3,051,807 8/1962 Huffman 337/400 X 2,833,894 5/1958 Weber et al. 337/309 1,827,137 10/1931 Blome 337/309X FOREIGN PATENTS 618,092 2/1949 Great Britain Primary Examiner Bernard A. Gilheany Assistant Examiner-Dewitt M. Morgan Attorneys-Auzville Jackson, .lr., Robert L. Marben and Candor, Candor & Tassone ABSTRACT: An electrical thermostat having a movable selector carried by the housing thereof. A temperature sensing device is carried by the housing and has a movable part facing in one direction. A first spring blade is carried by the housing and has a first contact. A second spring blade is carried by the housing and has a second contact cooperable with the first contact. The second spring blade is normally being urged toward the first contact and engages the movable part of the temperature sensing device to follow movement thereof while the first spring blade is normally being urged toward the second contact. Means are carried by the housing for overriding the first spring blade to tend to move the first contact away from the second contact, the selector having a part facing in the one direction and engaging the overriding means for positioning the overriding means relative to the housing and thus positioning the first contact relative to the second contact whereby the temperature sensing device is adapted to place the contacts in contact with each other when the temperature sensing device senses a temperature effect below a preselected temperature effect setting of the selector and is adapted to move the second contact away from the first contact when the temperature-sensing device senses a temperature effect above the preselected temperature effect of the selector means.

PATENTED NUVZ [9n SHEET 1 OF 5 FIG-4 3- MVQWQ INVENTOR BRANS WOLFE CHARLES n. DENIS FIG-3 THEIR ATTORNEYS PATENTED NOV 2 I971 SHEET 2 UF 5 3 3 3 N MM 9 9 80 RS TAE NRF

BBL

W Wow THEIR ATTORNEYS PATENTED m2 191:

SHEET 0F 5 42 I I Q I INVENTORS CHARLES o. BRANSON news 6. WOLFE THEIR ATTORNEYS PATENTEDNUVZ I971 '6 SHEET 5 OF 5 INVENTORS CHARLES o. BRANSON DENIS s. WOLFE MiM THEIR ATTORNEYS FUEL CONTROL SYSTEM AND PARTS THEREFOR OR THE LIKE This application is a divisional patent application of its copending parent application, Ser. No. 672,520, now U.S. Pat. No. 3,521,814 filed Oct. 3, 1967, and is assigned to the same assignee to whom the parent application is assigned.

This invention relates to an improved fuel control system for fuel-burning apparatus or the like as well as to improved parts for such a fuel control system or the like.

One of the features of this invention is to provide a control device wherein an electric thermostat is utilized to control an electrically operated gas regulating meansto tend to maintain a temperature effect of a burner means at a preselected temperature etfect selected by manually operated selector means, the selector means also controlling a valve member for interconnecting and disconnecting a source of fuel to the electrically operated regulating means for an on-off operation thereof.

In particular, the electric thermostat of this invention controls the fuel gas supply to the burner means by means of an electrically operated heat motor valve or solenoid valve or the like, while the valve member controls the fuelgas supply to the burner means upstream of the electrically operated valve.

Such control device can be directly mounted on a fuel supply manifold or be connected at a point remote from such manifold as desired, as will be apparent hereinafter.

Another feature of this invention is to permit the control device to be automatically modified to a lower holding temperature effect by the remote opening of a switch controlled by a clock or timer or the like wherein the housewife or the like can initially set the control device to maintain a relatively high cooking temperature in the oven for a preselected length of time, where y after the lapse of such time, the control device will automatically reduce the temperature in the oven to a lower warmth-retaining and noncooking temperature to be maintained in the oven until the housewife or the like terminates the operation of the oven.

In addition, the housewife or the like can manually change the temperature setting of the control device to atemperature lower than the previously described holding temperature, even while the remote clock or timer-operated switch remains open.

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

Another object of this invention is to provide improved parts for such a control system or the like.

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

FIG. 1 is a fragmentary, perspective view of a typical apparatus utilizing the control system and parts of this invention.

FIG. 2 is a schematic view illustrating the control system of this invention in its of position.

FIG. 3 is a view similar to FIG. 2 and illustrates the system in its "on" position.

FIG. 4 is a view similar to FIG. 2 and illustrates the system in its "keep warm" position.

FIG. 5 is a view similar to FIG. 4 and illustrates the system being utilized at a temperature setting below the keep warm" setting of FIG. 4.

FIG. 6 is a front view of the control device of this invention with the selector knob removed.

FIG. 7 is a cross-sectional view taken on line 7-7 of FIG. 6.

FIG. 8 is a side view of the control device of FIG. 6 and illustrates the fuel flow path therethrough.

FIG. 9 is a cross-sectional view taken on line 9-9 of FIG. 7.

FIG. 10 is a fragmentary, cross-sectional view taken on line l0- 10 of FIG. 7.

FIG. 11 is a cross-sectional view taken on line 1111 of FIG. 7.

FIG. 12 is a rear plan view of the valve member of the control device of FIG. 6.

FIG. 13 is a cross-sectional view taken on line 13-13 of FIG. 12.

FIG. 14 is a front plan view of the valve member of FIG. 12.

FIG. 15 is a front plan view of part of the selector means of the control device of FIG. 7.

FIG. 16 is a cross-sectional view taken on line 16-16 of FIG. 15.

FIG. 17 is a front plan view of another part of the selector means of the control device of FIG. 7.

FIG. 18 is a cross-sectional view taken on line 18-18 of FIG. 17.

FIG. 19 is a rear plan view of the selector part of FIG. 17.

FIG. 20 is an exploded, perspective view of certain parts of the control device of FIG. 7.

FIG. 21 is a schematic view of the control device of FIG. 7, partially in cross section, illustrating the control device in its off" position.

FIG. 22 is a view similar to FIG. 21 and illustrates the control device in its on position.

While the various features of this invention are hereinafter described and illustrated as being particularly adaptable for providing a fuel control system for a domestic oven or the like, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide a control means for other types of apparatus as desired.

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.

Referring now to FIG. I, the improved fuel control system of this invention is generally indicated by the reference numeral 30 and is being illustrated as providing a control system for a domestic range 31 having an oven chamber 32, the fuel control system 30 including a fuel supply manifold means 33 and a fuel control device 34 for interconnecting the fuel supply manifold 33 to a conduit means 35 leading to a burner means 36 for the oven 32. The conduit 35 has a solenoid operated valve means 37 or the like disposed therein to be controlled by an electric thermostat of the control device 34 in a manner hereinafter described, the electric thermostat of the control device 34 sensing the temperature effect in the oven 32 by means of a temperature-sensing bulb 38 being interconnected to the control device 34 by a capillary tube 39 in a manner hereinafter described.

In this manner, the housewife or the like can set a selector means 40 of the control device 34 at a selected temperature setting whereby the control device 34 will maintain the temperature effect in the oven 32 at the selected temperature effect in a manner hereinafter described, the control system 30 also having means for automatically reducing the temperature effect in the oven 32 to a lower temperature effect after the occurrence of an event, such as after the lapse of a preselected cooking time period, whereby the lower temperature effect may be maintained in the oven 32 until the housewife or the like changes the control device 34, as will be apparent hereinafter.

Referring now to FIG. 7, the control device 34 of this invention includes a housing means 41 having a flat valve surface 42 interrupted by an inlet port or opening 43 leading to an inlet passage means 44, FIG. 8, adapted to be fluidly interconnected to the gas supply manifold 33 in any suitable manner, such as by being directly attached thereto or being interconnected to such manifold 33 at a position remote therefrom by suitable conduit means. Similarly, the flat valve surface 42 is interrupted by an arcuate port or opening 45 leading to an outlet passage means 46, FIG. 8, in the housing means 41 to be interconnected to the conduit 35 that leads to the electrically operated valve means 37 of FIG. I, and, thus, to the burner means 36 for the oven 32.

A rotary disc valve member 47 is rotatably carried by the housing means 41 and is utilized for interconnecting and disconnecting the inlet port 43 of the valve surface 42 to and from the outlet port 45 thereof in a manner hereinafter described. As illustrated in FIGS. 12-14, the disc valve member 47 has a flat rear valve surface 48 interrupted by an arcuate recess 49 adapted to register with the port means 43 and 45 as hereinafter described, the valve member 47 having an opening 50 passing substantially therethrough and being of a substantially square cross-sectional configuration.

The disc valve member 47 has an annular projection means 51 on the front side 52 thereof to coincide with the recess 49 and is provided with three peripheral recesses 53 to interconnect the same with a spring drive means 54, as illustrated in FIGS. 7, and 16.

In particular, the spring drive means 54 has a substantially flat and circular part 55 suitably cut to define arcuate openings passing therethrough to add resiliency and define three legs 56 each having rearwardly extending tangs 57 adapted to be respectively received in the recesses 53 of the valve member 47 to not only drivingly interconnect the spring means 54 thereto so that the valve member 47 and spring means 54 will rotate in unison, but to also urge the valve surface 48 of the valve member 47 into sealing relationship with the valve surface 42 of the housing means 41 when the valve member 47 and spring means 54 are assembled to the housing 41 and held thereto by a cup-shaped retainer means 58 in the manner illustrated in FIG. 7.

The central portion of the spring means 54 has an opening means 59 passing therethrough and defines a substantially rectangular portion 60 to drivingly receive an extension 61 of a selector part 62 in the manner illustrated in FIG. 10.

The selector part 62 is best illustrated in FIGS. 17-19 and includes a front disclike member 63 having an opening 64 passing centrally therethrough and being integrally interconnected to the rearwardly extending flange 61 which terminates at a rear member 65 integrally interconnected to and having an opening 66 passing therethrough and coaxially aligned with the opening 64, as illustrated in FIG. 19. The flange 61 of the part 62 also has spring arms 67 extending traversely thereto to be urged by their natural resiliency into an annular recess 68, FIG. 7, of an adjusting member 69 having one end 70 fastened to the rear surface 71 of the front member 63 of the selector part 62 in coaxial alignment with the opening 64 to project through the opening 66 in the rear member 65 thereof, through the opening 59 of the spring member 54 and opening 50 of the valve member 47 and have its other end 72 threadedly received in a threaded bore 73 passing through the housing means 41.

The portion of the adjusting member 69 which is telescopically received in the opening 66 of the selector part 62 and the opening 50 of the valve member 47 has a cross-sectional configuration identical to the

openings

66 and 50, whereby the

parts

69, 47 and 62 will rotate in unison.

A C-shaped or other type of shaft member 74 has one end 75 secured to the front member 63 of the selector part 62 in the manner illustrated in FIG. 7 so that the other end 76 thereof can be secured to a selector knob 77. In this manner, rotation of the selector knob 77 relative to the housing means 40 of the control device 34 causes simultaneous rotation of the

selector part

62 and 54 and simultaneous rotation of the adjusting member 69. However, rotation of the adjusting member 69 causes axial movement of the adjusting member 69 relative to the housing means 41 through the threaded relationship between the end 72 thereof and the threaded bore 73.

The adjusting member 69 has a bore means 78 passing axially therethrough, with one end 79 being internally threaded to receive an adjusting screw 80 having a bifurcated end 81 accessible through the opening 64 in the front member 63 of the selector part 62 for calibration purposes. A tubular insulating member 82 is disposed in the bore 78 of the adjusting member 69 and has one end 83 abutting against the end 84 of the adjusting screw 80 while the other end 85 projects beyond the end 72 of the adjusting member 69 and carries a rivetlike member 86 for controlling an electrical thermostat means 87 of this invention now to be described.

The electrical thermostat unit 87 is disposed in a chamber 88 ofthe housing means 41 and includes four

spring blades

89, 90, 91 and 92, each having their right-hand ends in FIG. 7 cantilevered mounted in stacked relation to the housing means 41 by suitable insulating block means 93 and fastening means 94. The spring blade 89 carries an electrical contact 95 on the free end thereof and has a natural tendency to move the contact 95 upwardly in FIG. 7.

However, a leaf spring 96 has its right-hand end in FIG. 7 cantilevered mounted with the right-hand end of the spring blade 89 and has a natural bias to override the bias of the spring blade 89 and move the same downwardly in FIG. 7. The spring blade 89 has an opening 97 passing therethrough and telescopically receiving the rivet end 86 of the tubular member 85, whereby the position of the rivet end 86 limits the downward movement of the spring blade 89 under the influence of the overriding leaf spring 96, as the leaf spring 96 will abut the rivet end 86 of the tubular member in the manner illustrated in FIG. 7 to compact the lower end 83 of the tubular member 82 against the end 84 of the adjusting screw 80.

The spring blade carries an electrical contact 98 adjacent the free end 99 thereof and has a natural bias to tend to move the contact 98 downwardly in FIG. 7. However, the free end 99 of the spring blade 90 carries an abutment member 100 adapted to engage a movable wall 101 of an expansible ans collapsible power element 102. The movement of the contact 98 relative to the contact 95 is controlled by the movable wall or part 101 of the power element 102.

The power element 102 has another wall 103 cooperating with the wall 101 to define a fluid chamber therebetween which is disposed in fluid communication with the previously described capillary tube 39 of the temperature sensing bulb 38. The power element 102 is fixed to the housing means 41 by a threaded connector 104 and nut 105 in any suitable manner.

The spring blade 92 has a reversely curving free end 106 carrying an electrical contact 107 and has a natural bias to move the contact 107 downwardly in FIG. 7. However, the free end 106 of the spring blade 92 carries an abutment means 108 adapted to abut against an adjusting screw 109 threadedly disposed in an internally threaded bore 110 passing through the housing means 41. The threaded adjusting member 109 has a bifurcated end 111 to permit external adjustment of the screw 109 relative to the housing means 41 whereby the upper end 112 of the adjusting screw 109 can be positioned in a desired position and, thus, position the contact 107 in a desired position relative to the housing means 41 for a lowtemperature operation in a manner hereinafter described.

The spring blade 91 carries a contact 113 on the free end thereof and has a natural bias to tend to move the contact 113 downwardly to cooperate with the contact 107 in a manner hereinafter described. However, the spring blade 91 bears against the spring blade 90 whereby the position of the contact 113 relative to the contact 10 is also controlled by the movable part 101 of the power element 102.

The control device 34 of this invention can be utilized in the system 30 previously described and reference is now made to FIGS. 2-5 to illustrate the electrical circuit for the system 30.

In particular, it can be seen in FIG. 2 that a power source lead L1 is adapted to be electrically interconnected to the right-hand end of the switchblade 92 by a lead 114 whereby the fixed contact 107 is electrically interconnected to the lead L1. A branch lead 115 interconnects the lead 114 to the righthand end of the

switchblades

90 and 91 to electrically interconnect the

respective contacts

98 and 113 to the power source lead L1. However, the lead 115 has a clock timer operated electrical switch means 116 therein which only permits the lead L1 to be interconnected to the

switchblades

90 and 91 when the timer operated switch means 116 is disposed in its normally closed position, as illustrated in FIG. 2.

The power source lead L2 is interconnected to one side 117 ofa solenoid coil 118 of the valve means 37 in the conduit 35 by a lead 119. The other side 120 of the solenoid coil 118 is interconnected to the right-hand end of the switchblade 89 by a lead 121 whereby the contact 95 is electrically interconnected to the power source lead L2.

The operation of the control system 30 and the control device 34 will now be described.

As previously stated, the timer operated switch 116 is normally closed and when the selector knob 77 is disposed in its off position, as illustrated in FIGS. 2, 7 and 21, not only is the recess 49 of the valve member 47 disposed out of fluid communication with the inlet port 43 to prevent fuel from flowing from the manifold 33 to the conduit 45, but also the adjusting member 69 is in its outermost axial position relative to the housing means 41 to position the contact 95 fully away from the contact 98, so that the

contacts

98 and 95 cannot be placed in electrical contact with each other, regardless of the position of the movable wall part 101 of the power element 102. In this manner, the solenoid coil 118 cannot be placed across the power source leads L1 and L2, as the

contacts

95 and 98 will always be in a separated condition when the control device 34 is in its "off" position.

In the off position of the control device, the

contacts

107 and 113 are together, as illustrated in FIGS. 2 and 7. However, the valve 37 is not energized, as-the

contacts

98 and 95 are separated in this off" position of the control device 34.

When the housewife or the like desires to operate the oven 32 with a cooking temperature, the housewife or the like rotates the selector knob 77 in a clockwise direction from the position illustrated in FIG. 21 toward the maximum temperature setting position illustrated in FIG. 22 until the selector knob 77 is set at the desired cooking temperature, such as 325 F. or the like. With the control knob 77 rotated to any temperature setting thereof, it can be seen that the recess 49 of the valve member 47 will fluidly interconnect the inlet port 43 with the outlet port 45 to permit fuel to flow from the manifold 33 through the housing means 41 and the conduit 35 to the solenoid operated valve member 37. In addition, clockwise rotation of the selector knob 77 from its off" position to the desired temperature-setting position previously described causes axial inward movement of the adjusting member 69 to move the leaf spring 96 upwardly to a desired position whereby the bias of the spring blade 89 follows the upward movement of the leaf spring 96 to position the contact 95 at a temperature-setting position selected by the knob 77.

Since the oven 32 is at a temperature below the selected temperature, such positioning of the adjusting member 69 by the selector knob 77 places the contact 95 against the contact 98 and moves the

spring blades

90 and 91 upwardly therewith.

Thus, it can be seen that in this position of the control device 34, the coil 118 of the solenoid operated valve member 37 is placed across the power leads L1 and L2 in the manner illustrated in FIG. 3, because the switch 116 is closed and the

contacts

95 and 98 are in electrical contact with each other. Thus, the valve member 37 opens to permit fuel to flow from the control device 34 to the burner means 36 to be ignited by suitable igniting means.

The system 30 remains in the condition illustrated in FIG. 3 as long as the temperature effect produced by the burner means 36 is below the temperature setting of the selector knob 77. However, once the temperature in the oven 32 reaches or rises slightly above the selected temperature effect of the control knob 77, the temperature sensing bulb 38 has caused the power element 102 to expand in such a manner that the movable wall part 101 has moved upwardly in FIG. 7 a distance sufficient to carry the

spring blades

90 and 91 therewith and separate the contact 98 from the contact 95 to terminate the flow of current through the coil 118 so that the valve means 37 will close and terminate the flow of fuel through the burner means 36.

When the temperature effect in the oven 32 falls below the selected temperature effect of the knob 77, the temperaturesensing bulb 38 has caused the movable wall part 101 of the power element 102 in FIG. 7 to move downwardly a distance sufficient to again place the contact 98 into electrical contact with the contact 95 and again energize the coil 118 to open the valve means 37 and permit fuel to flow to the burner means 36.

Thus, it can be seen that the thermostat means 87 of this invention is adapted to cycle on and off the burner means 36 of the oven 32 to tend to maintain the temperature effect in the oven 32 at the temperature selected by the selector knob 77.

If the housewife or the like had set the timer-operated switch means 116 to open the switch 116 after the lapse of a predetermined cooking time, such as 2 hours or the like, the thermostat means 87 of the control system 30 would maintain the temperature effect in the oven 32 at the previously described 325 F., as set by the selector knob 77 for this 2- hour period in the manner previously described. However, when the 2-hour cooking period lapsed, the timer-operated switch 116 will automatically open in the manner illustrated in FIG. 4 to prevent the solenoid-operated valve 37 from having its coil 118 energized through the closing of the

contacts

98 and 95. Thus, the temperature effect in the oven 32 decreases, causing the movable wall part 101 of the power element 102 to move downwardly and the switchblades and 91 follow therewith and carry the switchblade 89 therewith as the bias of the

switchblades

90 and 91 is stronger than the upward bias of the switchblade 89, such downward movement of the switchblade 89 relative to the adjusting member 69 is permitted by the opening 97 in the blade 89.

Such downward movement of the

switchblades

90 and 91 continues until the switchblade 91 places the contact 113 into electrical contact with the contact 107 in the manner illustrated in FIG. 4, whereby it can be seen that the solenoid coil 118 is now placed across the power source leads L1 and L2 by the

closed contacts

113 and 107, even though the timeroperated switch means 116 is in its open condition because the contacts 98 and of the device 34 are always in contact with each other when the device 34 is in its keep warm" setting.

Thus, fuel is again supplied to the burner means 36 by the now energized valve means 37 to tend to maintain the temperature effect in the oven 32 at a warmth-retaining and noncooking temperature as previously set by the adjusting screw 109. In particular, the temperature sensing bulb 38 will cause the power element 102 to separate the

contacts

113 and 107 when the temperature effect in the oven 32 rises above the keep warm" temperature setting of the screw 109 and will place the

contacts

113 and 107 in electrical contact when the temperature effect in the oven 32 falls below the "keep warm" temperature.

Thus, the control system 30 of this invention, through the control device 34, will maintain the temperature effect of the oven 32 at its keep warm" temperature until the housewife or the like turns the selector knob 77 to its "off" position, as illustrated in FIG. 2.

However, should the control system 30 be in the keep warm condition illustrated in FIG. 4 wherein the timeroperated switch 116 is in its open" position and the housewife or the like desires to have the temperature effect in the oven 32 be maintained by the control device 34 at a temperature below the automatic keep warm temperature, as set by the adjusting screw 109, the housewife can turn the selector knob 77 to such lower temperature to reposition the contact 95 downwardly from the position illustrated in FIG. 4 to the position illustrated in FIG. 5, whereby even though the power element 102 maintains the

contacts

113 and 107 in electrical contact with each other, the temperature in the oven 32 will have to decrease to the lower temperature selected by the knob 77 in order to place the contact 98 into electrical contact with the contact 95 and complete the circuit across the coil 118 ofthe valve means 37.

Thus, the temperature sensing bulb 39 will cause the power element 102 to open and close the

contacts

98 and 95 to tend to maintain the temperature effect in the oven 32 at the low temperature setting set by the control knob 77. even though the switch means 116 is in its open position.

Accordingly, it can be seen that not only does this invention provide an improved control system for an apparatus or the like wherein a control device combines a valve member for controlling fuel flow with an electrical thermostat for maintaining a desired temperature effect of a burner means, but also this invention provides improved parts for such a control system or the like.

What is claimed is:

1. An electrical thermostat device comprising a housing means, a movable selector means carried by said housing means, a temperature-sensing means carried by said housing and having a movable part facing in one direction, a first spring blade carried by said housing and having a first contact, a second spring blade carried by said housing and having a second contact cooperable with said first contact, said second spring blade normally being urged toward said first contact and engaging said movable part of said temperature-sensing means to follow the movement thereof, said first spring blade normally being urged toward said second contact, and means carried by said housing means and overriding said first spring blade to tend to move said first contact away from said second contact, said selector means having means facing in said one direction and engaging said overriding means for positioning said overriding means relative to said housing and, thus, positioning said first contact relative to said second contact whereby said temperature-sensing means is adapted to place said contacts in contact with each other when said temperature-sensing means senses a temperature effect below a preselected temperature effect setting of said selector means and is adapted to move said second contact away from said first contact when said temperature-sensing means senses a temperature effect above said preselected temperature effect setting of said selector means.

2. An electrical thermostat device as set forth in claim 1 wherein overriding means comprises a leaf spring carried by said housing means and bearing against said first spring blade and said selector means. i

3. An electrical thermostat device as set forth in claim 2 wherein said first spring blade has an opening therein receiving said selector means whereby said second spring blade can move said first spring blade relative to said leaf spring and said selector means for an overshoot purpose.

4. An electrical thermostat device comprising a housing means, a movable selector means carried by said housing means, a temperature-sensing means carried by said housing and having a movable part, a first spring blade carried by said housing and having a first contact, a second spring blade carried by said housing and having a second contact cooperable with said first contact, said second spring blade normally being urged toward said first contact and engaging said movable part of said temperature sensing means to follow the movement thereof, said first spring blade normally being urged toward said second contact, means carried by said housing means and overriding said first spring blade to tend to move said first contact away from said second contact, said selector means positioning said overriding means relative to said housing and, thus, positioning said first contact relative to said second contact whereby said temperature-sensing means is adapted to place said contacts in contact with each other when said temperature-sensing means senses a temperature effect below a preselected temperature effect setting of said selector means and is adapted to move said second contact away from said first contact when said temperature-sensing means senses a temperature effect above said preselected temperature effect setting of said selector means, a fixed contact carried by said housing means, and a third spring blade carried by said housing means and having a third contact cooperable with said fixed contact, said third spring blade normally being urged toward said fixed contact and being operatively interconnected to said movable part of said temperature-sensing means to follow movement thereof whereby said temperaturesensing means is adapted to place said third contact in contact with said fixed contact when said temperature-sensing means senses a temperature effect below a second temperature effect and is adapted to move said third contact away from said fixed contact when said temperature-sensing means senses a temperature effect above said second temperature effect.

5. An electrical thermostat device as set forth in claim 4 and including adjusting means carried by said housing means to adjust the position of said fixed contact relative to said housing means to change said second temperature effect setting of said device.

6. in combination, an electrical power source, an electrically operated heating means, and an electrical thermostat device for interconnecting and disconnecting said electrical power source to said heating means to tend to maintain a preselected temperature effect of said heating means, said thermostat device having a movable selector means, said thermostat device having a temperature sensing means provided with a movable part facing in one direction, said device having a first spring blade provided with a first contact, said device having a second spring blade provided with a second contact cooperable with said first contact, said second spring blade normally being urged toward said first contact and engaging said movable part of said temperature-sensing means to follow the movement thereof, said first spring blade normally being urged toward said second contact, said device having means overriding said first spring blade to tend to move said first contact away from said second contact, said selector means having means facing in said one direction and engaging said overriding means for positioning said overriding means relative to said device and, thus, positioning said first contact relative to said second contact whereby said temperature-sensing means places said contacts in contact with each other to interconnect said electrical power source to said heating means when said temperature-sensing means senses a temperature effect below a preselected temperature effect setting of said selector means and moves said second contact away from said first contact to disconnect said electrical power source from said heating means when said temperature-sensing means senses a temperature effect above said preselected temperature effect setting of said selector means.

7. A combination as set forth in claim 6 wherein said overriding means comprises a leaf spring carried by said device and bears against said first spring blade and said selector means.

8. A combination as set forth in claim 7 wherein said first spring blade has an opening therein receiving said selector means whereby said second spring blade can move said first spring blade relative to said leaf spring and said selector means for an overshoot purpose.

9. In combination, an electrical power source, an electrically operated heating means, and an electrical thermostat device for interconnecting and disconnecting said electrical power source to said heating means to tend to maintain a preselected temperature effect of said heating means, said thermostat device having a movable selector means, said thermostat device having a temperature-sensing means provided with a movable part, said device having a first spring blade provided with a first contact, said device having a second spring'blade provided with a second contact cooperable with said first contact, said second spring blade normally being urged toward said first contact and engaging said movable part of said temperature-sensing means to follow the'movement thereof, said first spring blade normally being urged toward said second contact, said device having means overriding said first spring blade to tend to move said first contact away from said second contact, said selector means positioning said overriding means relative to said device and, thus, positioning said first contact relative to said second contact whereby said temperaturesensing means places said contacts in contact with each other to interconnect said electrical power source to said heating means when said temperature-sensing means senses a temperature effect below a preselected temperature effect setting of said selector means and moves said second contact away from said first contact to disconnect said electrical power source from said heating means when said temperatureses a temperature effect below a second temperature effect and moves said third contact away from said fixed contact to be adapted to disconnect said electrical power source from said heating means when said temperature-sensing means senses a temperature effect above said second temperature effect.

10. A combination as set forth in claim 9 wherein said device includes adjusting means to adjust the position of said fixed contact relative to said device to change said second temperature effect setting of said device.

Claims

2. An electrical thermostat device as set forth in claim 1 wherein overriding means comprises a leaf spring carried by said housing means and bearing against said first spring blade and said selector means.

4. An electrical thermostat device comprising a housing means, a movable selector means carried by said housing means, a temperature-sensing means carried by said housing and having a movable part, a first spring blade carried by said housing and having a first contact, a second spring blade carried by said housing and having a second contact cooperable with said first contact, said second spring blade normally being urged toward said first contact and engaging said movable part of said temperature sensing means to follow the movement thereof, said first spring blade normally being urged toward said second contact, means carried by said housing means and overriding said first spring blade to tend to move said first contact away from said second contact, said selector means positioning said overriding means relative to said housing and, thus, positioning said first contact relative to said second contact whereby said temperature-sensing means is adapted to place said contacts in contact with each other when said temperature-sensing means senses a temperature effect below a preselected temperature effect setting of said selector means and is adapted to move said second contact away from said first contact when said temperature-sensing means senses a temperature effect above said preselected temperature effect setting of said selector means, a fixed contact carried by said housing means, and a third spring blade carried by said housing means and having a third contact cooperable with said fixed contact, said third spring blade normally being urged toward said fixed contact and being operatively interconnected to said movable part of said temperature-sensing means to follow movement thereof whereby said temperature-sensing means is adapted to place said third contact in contact with said fixed contact when said temperature-sensing means senses a temperature effect below a second temperature effect and is adapted to move said third contact away from said fixed contact when said temperature-sensing means senses a temperature effect above said second temperature effect.

9. In combination, an electrical power source, an electrically operated heating means, and an electrical thermostat device for interconnecting and disconnecting said electrical power source to said heating means to tend to maintain a preselected temperature effect of said heating means, said thermostat device having a movable selector means, said thermostat device having a temperature-sensing means provided with a movable part, said device having a first spring blade provided with a first contact, said device having a second spring blade provided with a second contact cooperable with said first contact, said second spring blade normally being urged toward said first contact and engaging said movable part of said temperature-sensing means to follow the movement thereof, said first spring blade normally being urged toward said second contact, said device having means overriding said first spring blade to tend to move said first contact away from said second contact, said selector means positioning said overriding means relative to said device and, thus, positioning said first contact relative to said second contact whereby said temperature-sensing means places said contacts in contact with each other to interconnect said electrical power source to said heating means when said temperature-sensing means senses a temperature effect below a preselected temperature effect setting of said selector means and moves said second contact away from said first contact to disconnect said electrical power source from said heating means when said temperature-sensing means senses a temperature effect above said preselected temperature effect setting of said selector means, said device having a fixed contact and a third spring blade having a third contact cooperable with said fixed contact, said third spring blade normally being urged towards Said fixed contact and being operatively interconnected to said movable part of said temperature sensing means to follow said movement thereof whereby said temperature-sensing means places said third contact in contact with said fixed contact to be adapted to interconnect said temperature-sensing means senses a temperature effect below a second temperature effect and moves said third contact away from said fixed contact to be adapted to disconnect said electrical power source from said heating means when said temperature-sensing means senses a temperature effect above said second temperature effect.