US3692239A

US3692239A - Control system for a double burner oven or the like and improved parts and method for the same or the like

Info

Publication number: US3692239A
Application number: US114691A
Authority: US
Inventors: Francis S Genbauffe
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1971-02-11
Filing date: 1971-02-11
Publication date: 1972-09-19
Anticipated expiration: 1989-09-19

Abstract

This disclosure relates to a control system for a bake burner and a broil burner of a domestic oven or the like wherein a control device is adapted to interconnect a source of fuel to a conduit means leading to the bake burner and the broil burner, the conduit means having a diverter valve therein intermediate the control device and the burners with the diverter valve being so constructed and arranged that the same will direct the fuel issuing thereto from the control device only to the bake burner when the selector means of the control device is set for a baking operation and will only direct the flow of fuel issuing thereto to the broil burner when the selector means of the control device is set for a broiling operation. In addition, a safety valve is disposed in the conduit means either intermediate the control device and the diverter valve means or intermediate the diverter valve means and the bake burner to be only opened when a certain flame means exists at a bake pilot burner means for the bake burner, the control device thermostatically controlling the operation of the bake pilot burner means.

Description

United States Patent Genbaufie [451 Sept. 19, 1972 CONTROL SYSTEM FOR A DOUBLE BURNER OVEN OR THE LIKE AND IMPROVED PARTS AND METHOD FOR THE SAME OR THE LIKE [72] Inventor: Francis S. Genbaufie, Irwin, Pa.

[73] Assignee: Robertshaw Controls Company,

Richmond, Va.

[22] Filed: Feb. 11, 1971 [21] Appl. No.: 114,691

Related US. Application Data [63] Continuation of Ser. No. 670,648, Sept. 26,

1969, abandoned.

[52] US. Cl. ..236/15 A, 236/60 D [51] Int. Cl. ..F23n l/00, GOSd 23/02 [58] Field of Search.....236/l5 A, 68 A, 99; 126/273, 126/39 [56] References Cited UNITED STATES PATENTS 3,386,656 6/1968 Berquist ..236/15 A 1,877,763 9/1932 Hazard ..137/627.5 2,691,990 10/1954 Ashton et a1 ..137/627.5 X 3,232,534 2/1966 Branson ..236/15 A 3,236,448 2/1966 Willson ..236/15 A 3,233,830 2/1966 Branson et al.... .....236/68 3,312,396 4/1967 Willson ..236/15 A 3,391,867 7/1968 Zulian ..236/15 Primary ExaminerWilliam E. Wayner Attorney-Auzville Jackson, Jr., Robert L. Marben and Candor and Candor [57] ABSTRACT I This disclosure relates to a control system for a bake burner and a broil burner of a domestic oven or the like wherein a control device is adapted to interconnect a source of fuel to a conduit means leading to the bake burner and the broil burner, the conduit means having a diverter valve therein intermediate the control device and the burners with the diverter valve being so constructed and arranged that the same will direct the fuel issuing thereto from the control device only to the bake burner when the selector means of the control device is set for a baking operation and will only direct the flow of fuel issuing thereto to the broil burner when the selector means of the control device is set for a broiling operation. In addition, a

safety valve is disposed in the conduit means either in- 12 Claims, 33 Drawing Figures PATENTEDsEP 19 I972 SHEET [1211f 13 INVE NTOR FRANCIS SGENBAUFFE Mf/W HIS ATTORNEYS PATENTEDsEP 19 I972 3.692.239

SHEET 03 [1F 13 FIG?) INVE NBAUFFE NT FRANCIS S. GE

HIS ATTORNEYS PATENTEDSEP 19 I972 3,692,239

sum an 0F 13 IN VE N TOR FRANCIS S. GENBAUF FE HIS ATTORNEYS PKTENTEDSEP 19 I972 3.692.239

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=1 fl 41 245 Z Zia I Iii w I I s INVENTOR FRANCIS SGENBAUFFE FIG.I8

HIS ATTORNEYS CONTROL SYSTEM FOR A DOUBLE BURNER OVEN OR THE LIKE AND IMPROVED PARTS AND METHOD FOR THE SAME OR THE LIKE This application is a continuation of application Ser. No. 670,648, filed Sept. 26, I969, now abandoned.

This invention relates to an improved control system for a double-burner oven arrangement and to improved parts and to improved methods for such a control system or the like.

While control devices have been provided for efiectively directing a flow of fuel to a bake burner or to a broil burner of a single oven cooking cavity or chamber depending upon the position of a selector knob of the control device, this invention provides an improved control system for such bake and broil burners wherein a diverter valve is disposed in a conduit means leading from a control device to the bake and broil burners to be operated in such a manner that when the control device is set for a baking operation, the diverter valve will direct all fuel issuing into the conduit means from the control deviceonly to the bake burner and when the selector means of the control device is set for a broiling operation, the diverter valve means will direct all of the flow of the fuel issuing into the conduit means from the control device only to the broil burner.

In addition, this invention provides a control system wherein the broil burner can be operated by the control device of this invention at any selected temperature well below the normal broiling temperature for a broiling operation or the like.

Accordingly, it is an object of this invention to provide an improved fuel 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.

A further object of this invention is to provide an im proved method of operating 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 schematic view illustrating the improved control system of this invention.

FIG. 2 is an enlarged schematic view of part of the control system illustrated in FIG. 1 and illustrates schematically the control device utilized with the system of FIG. 1.

FIG. 3 is a cross-sectional view of the control device of the system of FIG. 1 and is taken on line 3-3 OF FIG. 4.

FIG. 4 1's a cross-sectional view of the control device of FIG. 3 and is taken on line 4-4 thereof.

FIG. 5 is an exploded perspective view of various parts of the control device of FIGS. 3 and 4.

FIG. 6 is a front view of the control device of FIGS. 3 and 4 with the selector knob and cooperating means removed to illustrate the control device in its off position.

FIG. 6A is a schematic view illustrating the disc valve member of the control device of FIGS. 3 and 4 when disposed in the off position of FIG. 6.

FIG. 6B is a cross-sectional view taken on line 63-- 6B of FIG. 4 to illustrate the clutching member of the control device when the control device is set in its off position of FIG. 6.

FIG. 7 is a view similar to FIG. 6 and illustrates the control device in a baking position thereof.

FIG. 7A is a view similar to FIG. 6A and illustrates the disc valve set in the baking position of FIG. 7.

FIG. 7B is a view similar to FIG. 6B and illustrates the clutching members of the control device when set in the baking position of FIG. 7.

FIG. 8 is a view similar to FIG. 6 and illustrates the control device of FIGS. 3 and 4 set in its broiling position.

FIG. 8A is a view similar to 6A and illustrates the disc valve member set in the broiling position of FIG. 8.

FIG. 9 is an enlarged front view of the selector knob means for the control device of FIGS. 3 and 4.

FIG. 10 is a schematic view of another control system of this invention.

FIG. 11 is a view similar to FIG. 2 and illustrates certain parts of the control system of FIG. 10.

FIG. 12 is a schematic view of another control system of this invention.

FIG. 13 is a schematic view of still another control system of this invention.

FIG. 13A is a schematic view illustrating the disc valve member of the control device of FIG. 13 when the control device is disposed in its off position.

FIG. 13B is a view similar to FIG. 13A and illustrates the system of FIG. 13in a baking position thereof.

FIG. 13C is a view similar to FIG. 13A and illustrates the disc valte member of the control device set in its broil position.

FIG. 14 is a schematic view of another control system of this invention.

FIG. 14A is a view similar to FIG. 6A and illustrates the disc valve member of the control device of the system of FIG. 14 set in its off position.

FIG. 14B is a view similar to FIG. 14A and illustrates the control device set in its bake position.

FIG. 14C is a view similar to FIG. 14A and illustrates the system of FIG. 14 when set in its broil position.

FIG. 15 is a schematic view of a modification of the system of FIG. 14.

FIG. 16 is a schematic view of still another control system of this invention.

FIG. 16A is a view similar to FIG. 6A and illustrates the disc valve member of the control device of FIG. 16 set in its off position.

FIG. 16B is a view similar to FIG. 16A and illustrates the control device of the system of FIG. 16 set in its bake position.

FIG. 16C is a view similar to FIG. 16A and illustrates the disc valve member of the control device of the system of FIG. 16 set in its broil position.

FIG. 16D is a view similar to FIG. 16A and illustrates the flame adjusting operation of the system of FIG. 16

' when set in its broil position.

FIG. 17 is a schematic view of another control system of this invention.

that the various features of this invention can be utilized singly or in any combination thereof to provide means for operating other control systems or the like.

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

Referring now to FIGS. 1 and 2, an improved control system of this invention is generally indicated by the reference numeral and includes a bake burner 21 and a broil burner 22 adapted to be disposed in a domestic cooking apparatus or the like to effect the cooking operation of a single cooking cavity or chamber by having a source of fuel 23 selectively directed thereto by a control device 24 of this invention in a manner hereinafter described. However, the control system 20 is so constructed and arranged that a selector means 25 of the control device 24 can be set to thermostatically control the operation of the broil burner 22 at any desired temperature setting well below the normal temperature setting for a broiling operation as will be apparent hereinafter.

As illustrated in FIGS. 1 and 2, the control device 24 includes a housing 26 having an inlet means 27 adapted to be fluidly interconnected to the fuel supply manifold 23 in any suitable manner and has an outlet means 28 interconnected to a conduit means 29 leading to the bake burner 21 and broil burner 22.

In particular, the conduit means 29 includes a first conduit 30 having one end 31 fluidly interconnected to the outlet 28 of the control device 24 and the other end 32 interconnected to an inlet 33 of a safety valve means 34. An outlet means 35 of the safety valve means 34 is interconnected to one end 36 of another conduit 37 of the conduit means 29 which has its other end 38 interconnected to an inlet 39 of a diverter valve means 40 of this invention.

The safety valve means 34 can be of the type disclosed in U.S. Pat. to Branson et al., No. 3,233,830, wherein the valve means 34 prevents fluid communication between its inlet means 33 and its outlet means 35 when a flame detector means 41 senses that a certain flame means does not exist at a bake pilot burner means 42 for the bake burner 21. For example, the bake pilot burner means 42 can be of the type disclosed in the aforementioned U.S. Pat. to Branson et al. or of the type disclosed in the U.S. Pat. to Riehl, No.

3,308,871, wherein the same is adapted to be continuously supplied a small amount of fuel from the control device 24 to maintain a continuously burning small standby flame which is not sensed by the detector means 41. However, when the bake pilot burner means 42 is additionally supplied fuel by the control device 24 in a manner hereinafter described, the bake pilot burner means 42 creates a large heater flame that is detected by the detector means 41 to cause the safety valve 34 to open and remain open as long as such heater flame exists at the bake pilot burner means 42 to fluidly interconnect the conduit 30 with the conduit 37.

The diverter valve means 40 has a pair of

outlets

43 and 44 respectively interconnected to ends 45 and 46 of

conduits

47 and 48 forming part of the previously described conduit means 29 and respectively having the other ends 49 and 50 thereof fluidly interconnected to the broil burner 22 and bake burner 21.

The diverter valve means 40 is so constructed and arranged that a first valve member 51 is pivotally mounted at 52 and is normally biased to an open position thereof to maintain the outlet means 44 normally opened. A second valve member 53 is pivotally mounted at 54 and is normally biased to be in a closed position to normally close the outlet means 43.

A movable wall 56 of a power element 57 for the diverter valve 40 is so constructed and arranged that when the same is in a collapsed condition as illustrated in FIG. 1, the same permits the valve member 51 to be in an open position and the valve member 53 to be in a closed position. However, when the power element 57 is expanded for a broiling operation in a manner hereinafter described, the movable wall 56 thereof moves upwardly to first cause closing of the valve member 51 against the outlet means 44 before the movable wall 56 will cause opening movement of the valve member 53 away from the outlet means 43 for a purpose hereinafter described.

The interior of the power element 57 is interconnected to a bulb 59 by a capillary tube 60 so that when the bulb 59 senses that no certain flame means exists at a broil pilot burner means 61 for the broil burner 22, the power element 57 collapses and has the movable wall 56 thereof moved downwardly in FIG. 1 a sufficient distance so that the spring means of the diverter valve means 40 will cause the valve member 51 to completely close the outlet means 43 of the diverter valve 40 and fully open the outlet means 44 thereof. However, when the certain flame means exists at the broil pilot burner means 61, the bulb 59 causes the power element 57 to expand in such a manner that movable wall 56 thereof moves upwardly in opposition to the force of the spring means a distance sufficient to first cause the valve member 51 to fully close the outlet means 44 of the diverter valve means 40 and, thereafter, cause the valve member 53 to move downwardly and fully open the outlet means 43.

The control device 24 of this invention is so constructed and arranged in a manner hereinafter set forth, that when the selector means 25 is set in a position for a broiling operation, the control device 24 directs fuel through a conduit means 62 to a conventional pressure sensing switch means 63 that will permit the fuel to pass therethrough to a conduit means 64 leading to the broil pilot burner means 61. However, the pressure sensing switch means 63 is so constructed and arranged that when the fuel is directed thereto by the control device 24 through the conduit means 62 in a manner hereinafter described, the same automatically closes an electrical switch 65 to interconnect an electrical lead 66 with an electrical lead 67. g

The lead 66 is electrically interconnected to one end 68 of a primary coil 69 of an electrical transformer means 70, the other end 71 of the coil 69 being electrically interconnected to a power source lead L by a lead 72. The lead 67 is interconnected to a terminal 73 of an electrical switch 74 operated by the end of the valve member 53 of the diverter valve means 40 in a manner hereinafter described. Another terminal 75 of the electrical switch 74 is interconnected to the other power source lead L, by a lead 76.

The transformer means includes a secondary winding or coil 77 having one side 78 interconnected to one side 79 of an ignition coil 80 by a lead 81 while the other side 82 of the winding 77 is interconnected to the other side 83 of the ignition coil 80 by a lead 82.

The general operation of the control system illustrated in FIG. 1 will now be described.

When the selector means of the control device 24 is disposed in its off position, the control device 24 prevents the source of fuel 23 from being interconnected to the conduit of the conduit means 29 and also prevents any additional amount of fuel from being directed to the bake pilot burner means 42 through conduit means 84 to create the previously described large heater flame at the bake pilot burner means 42 whereby the safety valve means 34 is in a closed position to prevent fluid communication between the inlet means 33 and outlet means thereof even though a small standby flame is continuously burning at the bake pilot burner means 42. Also, when the selector means 25 of the control device 24 is disposed in its off posi- 1 tion, no fuel is directed by the control device 24 to the conduit means 62 leading to the burner pilot means 61 whereby the detector 59 causes the diverter valve to be disposed and maintained in the position illustrated in FIG. 1 wherein the valve means 51 closes off the outlet means 43 leading to the broil burner 22 and fully opens the outlet means 44 leading to the bake burner 21 even though no fuel is issuing thereto.

When the selector means 25 is moved to a position for a baking operation in a manner hereinafter described, the control device 24 does not supply fuel to the broil pilot burner means 61 whereby the diverter valve means 40 will remain in the position illustrated in FIG. 1. However, since the temperature in the oven is below the temperature selected by the selector means 25, the control device 24, in a manner hereinafter described, supplies an additional amount of fuel through the conduit 84 to create the previously described large heater flame at the bake pilot burner means 42 to be detected by the detector means 41 which will open the safety valve means 34 to interconnect the inlet means 33 thereof with the outlet means 35. Also, when the selector knob 25 is set at any on position, the same interconnects the source of fuel 23 with the conduit means 30 whereby fuel now can pass through the opened safety valve means 34 and be directed by the diverter valve 40 to the bake burner 41 to be ignited by the bake pilot burner means 42.

The control device 24 continuously supplies fuel to the bake burner 21 to heat the oven until temperature sensing bulb 85 of the control device 24 determines that the temperature of oven is at or above the tem perature selected by the knob 25 whereby the control device 24, in a manner hereinafter described, will terminate the flow of the additional fuel through the conduit 84 leading to the bake pilot burner means 42 so that the heater flame at the bake pilot burner means 42 will no longer exist. Thus, the detector 41 will close the safety valve 34 to prevent fuel from being directed to the bake burner 21. However, when the temperature in the oven falls below the temperature selected by the knob 25, the bulb means 85 will again cause the control device 24 to create the large heater flame at the bake pilot burner means 42 to open the safety valve 34 in the manner previously described to permit fuel to again issue from the main burner means 21 and be ignited by the bake pilot burner means 42.

Thus, it can be seen that in any baking operation selected by the selector means 25 of the control device 24, the bake burner means 21 will be cycled on and off by the control device 24 to tend to maintain the temperature effect in the oven at the temperature efiect selected by the selector knob 25, such baking operation not effecting the operation of the broil burner 22.

When the housewife or the like desires to utilize the control system 20 for'a broiling operation, the housewife sets the selector knob 25 in a broiling position thereof in a manner hereinafter described whereby not only is the additional amount of fuel supplied by the control device 24 through the conduit means 84 to create the heater flame at the bake pilot burner means 42 to open the safety valve 34, but also fuel is directed by the control device 24 through the conduit 62 to pass through the pressure sensing switch means 63 and issue from the broil pilot burner means 61. As the fuel is directed through the switch means 63 by the control device 24 in its broil setting, the switch means 65 thereof closes to place the primary winding 69 of the transformer 70 across the power source leads L and L to create a current flow in the secondary winding 77 of the transformer means 70 whereby the igniter coil 80 is energized to ignite the fuel now issuing from the broil pilot burner means 61. Once the broil pilot burner means 61 is ignited, the now continuously burning flame at the broil pilot burner means 61 is detected by the detector means 59 to cause the movable wall 56 of the power element 57 to move upwardly in FIG. 1 and first close the outlet means 44 thereof before opening the outlet means 43 whereby the fuel being directed to the diverter valve means 40 by the opened valve safety means 34 can only be directed by the diverter valve means 40 to the broil burner 22 and not to the bake burner 21 However, as the valve member 53 of the diverter valve means 40 is moving downwardly to open the outlet 43, the end of the valve member 53 trips a plunger 86 of the switch 74 to disconnect the

terminals

73 and 75 thereof whereby the ignition coil will cease to operate as the primary winding 69 of the transformer means 70 is no longer placed across the power source leads L and L The switch 74 is reset to again interconnect the

terminals

73 and 75 when the valve member 53 moves from its open position back to its 1 closed position when the control device 24 is subsequently turned to its off position or to a baking position to terminate the flow of fuel to the broil pilot burner 61.

Thus, the fuel issuing from the broil burner 22 by the diverter valve means 40 will be ignited by the broil pilot burner means 61 and will be continuously supplied fuel by the control device 24 as long as the temperature in the oven is below the temperature effect selected by the selector means 25 for the broiling operation.

However, should the temperature in the oven exceed the temperature effect selected by the knob 25 during the broiling operation, the control device 24, in a manner hereinafter described, will terminate the flow of the additional amount of fuel through the conduit means 84 whereby the heater flame at the bake pilot burner means 42 will no longer exist and the safety valve means 34 will close to prevent fuel from being directed to the broil burner means 22. However, fuel is still being supplied by the control device 24 to the broil pilot burner means 61 so that a flame still burns at the broil pilot burner means 61.

Subsequently, when the temperature effect in the oven falls below the selected temperature effect, the

j control device 24 will again supply the additional amount of fuel through the conduit means 84 to create the heater flame at the bake pilot burner means 42 so that the safety valve 34 will again open to permit fuel to issue to the broil burner 22 to be ignited by the broil pilot burner means 61.

However, the control system 20 of this invention is so constructed and arranged that when the control device 24 is set for a normal high temperature broiling operation, the flame at the broil burner 22 will never go out as described above, but when the selector means 25 is set for a low temperature effect broiling operation, such as for a rotisserie operation, the broil burner 22 will be cycled on and off in the above manner.

The particular details of the control device 24 of this invention for effecting the above operation of the control system 20 will now be described.

The control device 24 includes a disc valve member 87, HO. 2, interconnected to the selector means 25 so that when the selector means is moved to an on position thereof in a manner hereinafter described, the disc valve 87 not only interconnects the inlet 27 with the I outlet 28, but also interconnects the inlet 27 with a passage means 88 leading to a chamber 89 defined by a valve seat member 90 carried by the housing 26. The chamber 89 is separated from a chamber 91 by a valve seat 92 on the valve seat member 90, the valve seat 92 being opened and closed by a valve member 94 urged to the closed position by a compression spring 95.

An axially movable fulcrum pin 96 is carried by the housing 26 in such a manner that the axial position of the fulcrum pin 96 relative to the housing 26 is controlled by the selector or control knob 25 in a manner hereinafter described. The fulcrum pin 96 has a rounded end 97 provided with a cylindrical projection 98 passing through a suitable aperture in a lever 99 whereby the lever 99 is fulcrumed on the end 97 of the fulcrum pin 96.

One end 100 of the lever 99 bears against a movable wall 101 of an expansible and contractible element 102 having a wall 103 fixed to the housing 26, the interior of the expansible and contractible element 102 being interconnected to the oven temperature sensing bulb 85 by a conduit 104. The movable wall 101 of the expansible and contractible element 102 carries a valve member 105 for opening and closing a valve seat 106 in a manner hereinafter described.

The other end 107 of the lever 99 is adapted to engage a plunger 108 carried by the valve seat member 90 and engaging the valve member 94, the end 107 of the lever 99 being urged in a clockwise direction in FIG. 2 by a compression spring 109. Thus, the opening and closing of the valve member 94 is controlled by the lever 99 in relation to the temperature sensed by the bulb 85 and the axial position of the fulcrum pin 96 in a manner hereinafter described.

The chamber 91 of the housing 26 is interconnected to a passage means 110 leading to a bore 111 in the housing 26, an adjusting key 112 being rotatably disposed in the bore 111 and having a longitudinal bore 113 interconnected to the exterior of the key 112 by transverse bores 114 and 115. The longitudinal bore 1 13 of the adjusting key 1 12 is disposed in communication with a passage 116 leading to the conduit 84 interconnected to the bake pilot burner means 42.

Another passage 117 is formed in the housing 26 and is interconnected with the inlet passage 27 at a point upstream from the disc valve 87 as well as to a filter chamber 118. The filter chamber 118 is interconnected to a passage 119 leading to the bore 111 in the manner illustrated in FIG. 2, the passage 119 having an orifice 120 therein.

Thus, it can be seen that when the adjusting key 112 is disposed in the on position, as illustrated in FIG. 2, fuel from the supply conduit 23 is adapted to pass through the

passages

117 and 119 to the passage 115 of the adjusting key 112 and, thus, to the bake pilot burner means 42 to provide the previously mentioned small standby flame, which does not affect the safety valve means 34.

However, when the disc valve 87 is moved to an opened position for a baking operation or a broiling operation and the valve member 94 is moved to an opened position in a manner hereinafter described, the additional fuel being supplied through the passage 110 to the passage 114 of the adjusting key 112 causes the bake pilot burner means 42 to provide the previously described large heater flame which is sensed by the bulb 41 and causes the safety valve means 34 to open. However, when the valve member 94 closes, the additional supply of fuel to the pilot burner 42 is terminated whereby the large heater flame ceases to exist, even though the small standby flame continues, whereby the safety valve 34 will close.

Thus, as the valve member 94 cycles between its opened and closed positions in a manner hereinafter described, the safety valve means 34 is cycled on and off to maintain the temperature of the oven at a temperature selected by the control knob 25 in the manner previously described.

As illustrated in FIGS. 4, 5 and 6A, the housing means 26 defines a flat valve surface 121, interrupted by the spaced inlet 27 and an outlet 122 adapted to be interconnected together by a groove 123 in the disc valve 87.

In particular, the groove 123 in the disc valve 87 interrupts a valve surface 124 thereof with the valve surface 124 being disposed in sealing and sliding contact with the valve seat surface 121 of the housing 26, the disc valve 87 having an opening 125 passing therethrough and loosely receiving the end 126 of the fulcrum pin 96.

As illustrated in FIG. 5, the disc valve 87 has a pair of spaced arcuate embossments 127 formed on the side 128 thereof and a smaller substantially rectangular embossment 129 intermediate the embossments 127 for a purpose hereinafter described A cup-shaped member 130 forms part of the housing means 26 and is telescopically disposed over the disc valve 87, the member 130 having an aperture 131 passing there through in the closed end 132 thereof. The closed end 132 has a cam slot 133 formed therein and defining opposed camming edges 134 and 135 best illustrated in FIGS. 6 and 7. In addition, a pair of apertures 136 pass through the wall 132.

A C-shaped shaft 137 has one end 138 thereof interconnected to a plate member 139 having three outwardly projecting

tangs

140, 143 and 142. In addition, rearwardly directed tangs 141 are formed in the plate member 139 and are adapted to register with apertures 144 formed on another plate member 145.

The plate member 145 has a bent over tang 146 provided with a slot 147 and a pair of ears 148 having aper tures 149 passing therethrough. The

members

139 and 145 are adapted to be assembled together with another tang 150 of the member 139 received in the slot 147 of the member 145 and with the ears 148 of the member 145 passing through slots 151 of the plate member 139 and pinned thereto by a pin means 152 passing through the apertures 149. In this manner, rotation of the shaft 137 by the control knob 25 causes like rotation of the plate member 145.

The plate member 145 carries a tubular extension 153 both internally and externally threaded, the tubular extension 153 adapted to be threadedly received in a threaded bore 154 of a member 155 fixed in the aperture 131 of the housing part 130.

An adjusting screw 156 is threaded in the tubular part 153 of the plate 145 and has an end 157 adapted to abut the end 126 of the fulcrum pin 96.

Thus, rotation of the control knob 25 fastened on the other end 158 of the C-shaped shaft 137 causes the member 153 to be threaded into or out of the fixed threaded member 155 to adjust the axial position of the fulcrum pin 96.

A bowed spring-like washer 159 is provided and has tangs 160 adapted to register in the apertures 136 of the housing part 130, the spring means 159 having reversely directed tangs 161 adapted to be received in notches 162 in a washer-like member 163, the spring member 159 and washer-like member 163 being disposed between the closed wall 132 of the housing part 130 and the plate member 145 to place an outward force on the plate-like member 145, and, thus provide feel" in adjusting the rotational position of the knob 25 relative to the housing 26.

A spring retainer 164 is provided and has outwardly directed tangs 165 adapted to rest on the embossments 127 of the disc valve 87 and another tang 166. Another spring retainer 167 is provided and has an outwardly directed tang 168 similar to tang 166 of the spring retainer 164,

retainers

164 and 167 respectively having

openings

169 and 170 passing therethrough so that the same can be telescoped on the fixed threaded member 155. A compression spring 171 is adapted to be disposed between the

spring retainers

164 and 167 to compact a clutch member 172 against the inside surface of the wall 132 of the housing part 130.

The clutch part 172 has a pair of depending flanges 173 defining a notch 174 therebetween adapted to not only receive the

tangs

168 and 166 of the

spring retainers

167 and 164, but to also receive the rectangular embossment 129 of the disc valve 87. In addition, the clutch member 172 has an outwardly directed tang 175 adapted to pass through the cam slot 133 of the housing part 130, the clutch part or drive member 172 having an aperture 176 passing therethrough to loosely receive the fixed member 155.

The operation of the control device 24 as utilized in the system of this invention, with the parts heretofore described, will now be described.

Assuming that the control knob 25 is disposed in its off" position as illustrated in FIGS. 2, 6, 6A and 6B, the groove 123 of the disc valve 87 is in such a position that the same does not interconnect the inlet 27 with the outlet 122 nor the inlet 27 with the passage means 88 whereby no fuel issues from the bake burner 21 and only a small standby flame exists at the bake pilot burner means 42 as the adjusting key 112 is normally disposed in the on position as illustrated in FIG. 2.

When the operator desires to .turn on the oven for a set baking temperature thereof, the operator grasps the knob 25 and rotates the same in a counterclockwise direction as illustrated in FIG. 7 whereby rotation of the knob 25 causes like rotation of the plate 139 whereby the tang 140 of plate 139 bears against the tang 175 of the drive member 172 to cause like rotation therewith. As the drive member 172 is being rotated, the same, through the notch 174 thereof, rotates the

spring retainers

167 and 164 as well as the disc valve 87 to bring the groove 123 of the disc valve 87 in such a position that the same fully interconnects the inlet 27 with the outlet 122, as well as to have a groove 177 of the valve member 87 interconnect a ranch inlet port 178 of the housing 26 to the passage 88 as illustrated in FIG. 7A.

However, when the disc valve 87 is rotated to its fully on position, it can be seen that the edge of the cam slot 133 slides the drive member 172 radially outwardly to the position illustrated in FIGS. 7 and 73 whereby the tang of the plate member 139 is no longer in engagement with the tang 175 of the drive member 172 so that the control knob 25, when further rotated in a counterclockwise direction for setting the desired baking temperature does not further rotate the disc valve 87 from its fully on position as illustrated in FIGS. 7, 7A and 7B. Thus, the sliding movement of the drive member 172 declutches the disc valve 87 from the control knob or manipulator means 25.

During the rotational movement of the control knob 25 from its position to a set baking temperature position thereof, the threaded member 153 of the plate is backed out of the fixed threaded member in such a manner that the fulcrum pin 96 is adjusted to a new position thereof to the right in FIGS. 2, 3, and 4 as selected by the temperature setting of the control knob 25.

This axial movement of the pin 96 from its off position to its selected baking temperature position permits the compression spring 109 to pivot the lever 99 on the fulcrum pin 96 in such a manner that the pin 108 carried by the valve seat member 90 is moved to the right in FIG. 2 to open the valve member 94 away from the valve seat 92 so that fuel in the passage 88 is now adapted to pass into the chamber 91 and, thus, to the bake pilot burner means 42 to create the large heater flame at the bake pilot burner means 42 whereby the bake burner 21 will be operated in the manner previously described.

Should a malfunction occur in the control device 24 of this invention, so that the valve member 94 will not close whereby the bake burner 21 remains on in a runaway condition, the increased temperature in the oven will cause the movable wall 101 of the power element 102 to further move to the right in FIG. 2 to bring the valve member 105 closer to the valve seat 106 to throttle the flow of fuel to the bake burner 21 in such a manner that the bake burner 21 cannot produce a temperature in the oven above a predetermined safe temperature. Such safety feature also applies for the broiling operation hereinafter described.

When it is desired to turn off the system of this invention, the operator rotates the control knob 25 back to the off" position illustrated in FIG. 6. As the plate 139 is being rotated to its off position, the tang 142 thereof engages the tang 175 of the drive member 172 and rotates the drive member 172 therewith, whereby the disc valve 87 is rotated back to its off position, the drive member 172 sliding radially inwardly relative to the disc valve 87 by means of the edge 134 of the cam slot 133 in the housing part 130 from the position illustrated in FIGS. 7 and 7A back to the position illustrated in FIGS. 6 and 6A. As the control knob 25 is rotated back to its off position, the tang 175 on the drive member 172 engages the end of the slot 133 when the control knob is disposed in its off position whereby the cam slot 133 determines the off position of the control knob 25.

When it is desired to utilize the control system 20 of this invention for a broiling operation, the housewife or the like turns the selector means or control knob 25 in a counterclockwise direction in the manner previously described through the bake range until the control knob 25 as illustrated in FIG. 9 has the broil setting thereof placed adjacent the mark 179 on an outer stationary ring 180 of the housing means 26. As the control knob 25 is being slowly rotated and as the same approaches the broil setting thereof, it can be seen in FIG. 8 and 8A that the tang 143 of the member 139 engages the tang 175 of the drive member 172 to rotate the same in a counterclockwise direction until the tang 175 engages the lower end of the cam slot 133 which is the broil position of the control knob 25. This further rotation of the drive member 172 causes further like rotation of the valve member 87 whereby the a groove 177 of the valve member 87 additionally interconnects the branch inlet port 178 of the housing 26 with the passage means 181 in the housing means 26 that leads to the conduit 62 for the broil pilot burner means 61.

If desired, the valve member 87 can have an outwardly directed actuator 182 adapted to close a normally open switch means 183 when the valve member 87 has been moved to its broil position as illustrated in FIG. 8A whereby the closed switch means 183 will place a broil" indicating light member 184 across the power source lead L and L to indicate to the housewife or the like that the control knob 25 has been set for a broiling operation which occurs in the manner previously described because the diverter valve is now under the control of the broil pilot burner means 61 to divert the flow of fuel from the control device 24 to only the broil burner 22 to be operated in the manner previously described.

Since a normal broiling operation takes place at approximately 625 F. or the like, the rotation of the control knob 25 to the broil position previously described has adjusted fulcrum pin 96 in such a manner that the valve member 94 is completely moved away from the valve seat 92 so that the large heater flame at the bake pilot burner means 42 remains constant to maintain the safety valve means 34 in an open condition and produce a continuous flame broiling operation by the broil burner 22. However, should the temperature sensing bulb 85 sense that the temperature in the oven is exceeding the aforementioned 625 F. or the like, the movable wall 101 of the power element 102 moves to the right in FIG. 2 to cause the valve member 105 to produce a throttling down or modulating action on the flow of fuel passing through the valve seat 106 well before the valve member 94 will close against its valve seat 92 so that the flame at the broil burner 22 will not go out and will not tend to exceed the aforementioned 625 F. temperature in the oven for the system 20.

It may be found that the housewife or the like desires to utilize the broil burner 22 for a cooking operation at a temperature well below the aforementioned 625 F. normal broiling temperature for the oven.

Therefore, the housewife or the like, after setting the control knob 25 at the broil setting thereof previously described so that the indicating light 184 will be turned on and the valve member 87 will be disposed in the position illustrated in FIGS. 8 and 8A, the housewife can then rotate the control knob 25 in a clockwise direction back to a desired temperature setting for the oven whereby the fulcrum pin means 96 will be so adjusted to tend to maintain the temperature in the oven at the selected broiling temperature by the bulb 85 causing the opening and closing of the valve member 94 to cycle the safety valve means 34 between its opened and closed positions to maintain the tem perature in the oven at the selected broiling temperature without causing the bake burner 21 to be operated as the valve member 87 is maintaining the flow of fuel to the broil pilot burner means 61.

Therefore, it can be seen that this invention provides an improved control system for a double burner oven or the like as well as improved parts and method for such system or the like.

In addition, the system 20 of this invention overcomes a particular disadvantage of prior known all gas systems where both burners become operating under conditions of loss of control during a baking operation, such as by a broken temperature sensing bulb means or the like.

In particular, this invention overcomes the above disadvantage while still providing the single dial operation for the bake and broil temperature settings in a manner not provided by prior known systems.

For example, under conditions of loss of control, such as by a broken thermostat bulb 85, only the bake burner 21 of this invention will be operated as the rise in temperature in the oven will not cause operation of the broil burner 22 as in prior known systems wherein a thermally operated broil safety valve will open when the oven temperature reaches a temperature sufficient to cause the flame detector for the broil safety valve to open whereby for this prior known type of system, a separate main flow broil selector cock is normally required in addition to a selector cock for a baking operation.

However, in the control systems of this invention, when such a high temperature is reached, the diverter valve 40 acts first to reduce or modulate the input flow of fuel to the bake burner 21 because, as the movable wall 56 of the lower element 57 moves upwardly, the

Claims

1. In combination, a bake burner, a broil burner, a source of fuel, a conduit means leading to said bake burner and to said broil burner, a control device for interconnecting said source of fuel to said conduit means, a diverter valve means in said conduit means intermediate said control device and said burners and having two outlets, said diverter valve means having valve member means which in one condition thereof maintains one of said outlets in an open condition thereof and the other of said outlets in a closed condition thereof and when in another condition thereof maintains said one outlet in a closed condition thereof and said other outlet in an open condition thereof, said control device having a selector means for selecting a a broiling operation or a baking operation, said control device tending to cause said diverter valve means to direct fuel issuing into said conduit means from said control device out of said one outlet only to said bake burner when said selector means is set for a baking operation and tending to cause said diverter valve means to direct fuel issuing into said conduit means from said control device out of said other outlet only to said broil burner when said selector means is set for a broiling operation, said diverter valve means always first terminating and thereafter preventing any fuel flow to said bake burner before permitting any fuel flow to said broil burner when said selector means is set for a broiling operation, a broil pilot burner means for said broil burner, and means responsive only to said broil pilot burner means and being operatively interconnected to said valve member means of said diverter valve means to cause said valve member means to be in said other condition thereof to tend to direct fuel only to said broil burner when a certain flame means exists at said broil pilot burner means and to be in said one condition thereof to tend to direct fuel only to said bake burner when said certain flame ceases to exIst at said broil pilot burner means.

2. A combination as set forth in claim 1 wherein said control device includes thermostatic means for tending to maintain a temperature effect of said bake burner at a temperature effect selected by said selector means for a baking operation.

3. A combination as set forth in claim 1 wherein said control device includes thermostatic means for tending to maintain a temperature effect of said broil burner at a temperature effect selected by said selector means for a broiling operation.

4. A combination as set forth in claim 3 wherein said selector means can select a temperature effect to be maintained by said broil burner from a relatively high temperature effect to a relatively low temperature effect.

5. A combination as set forth in claim 1 and including a safety valve means in said conduit means intermediate said control device and said diverter valve means.

6. A combination as set forth in claim 5 and including a bake pilot burner means for said bake burner, and means operatively interconnected to said safety valve means to open said safety valve means to permit fuel issuing from said control device into said conduit means to pass to said diverter valve means only when a certain flame means exists at said bake pilot burner means and to close said safety valve means to prevent fuel issuing from said control device into said conduit means from passing to said diverter valve means when said certain flame means ceases to exist at said bake pilot burner means.

7. A combination as set forth in claim 6 wherein said control device has means for directing fuel to said bake pilot burner means to create said certain flame means.

8. A combination as set forth in claim 7 wherein said last-named means of said control device is thermostatically operated in response to the temperature effect produced by said bake burner when said selector means is set for a baking operation.

9. A combination as set forth in claim 7 wherein said last-named means of said control device is thermostatically operated in response to the temperature effect produced by said broil burner when said selector means is set for a broiling operation.

10. A combination as set forth in claim 7 wherein said last-named means of said control device is only adapted to direct fuel to said bake pilot burner means to create said certain flame means when said selector means is set for either a baking operation or a broiling operation.

11. A combination as set forth in claim 1 wherein said control device has means for directing fuel to said broil pilot burner means to create said certain flame means when said selector means is set for a broiling operation.

12. A combination as set forth in claim 11 and including ignition means for igniting the fuel issuing from said broil pilot burner means.