US3490434A

US3490434A - Ignition means and method for a cooking apparatus or the like

Info

Publication number: US3490434A
Application number: US670309A
Authority: US
Inventors: Charles D Branson; Francis S Genbauffe; Denis G Wolfe
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1967-09-25
Filing date: 1967-09-25
Publication date: 1970-01-20
Anticipated expiration: 1987-01-20

Description

Jan. 20, 1970 c. D. BRANSON ETAL 3, 9

IGNITION MEANS AND METHOD FOR A COOKING APPARATUS OR THE LIKE Filed Sept. 25, 1967 14 24 35 If z/ E TORS 68 CHARllE gaRANsoN 3g 67 t 44 FRANCIS S.GENBAUFFE 2 65 g DENIS s. WOLFE 4/ 43 T i4 3/ THEIR ATTORNEYS United States Patent 3,490,434 IGNITION MEANS AND METHOD FOR A COOKING APPARATUS OR THE LIKE Charles D. Branson, Greensburg, Francis S. Genbautfe, Irwin, and Denis G. Wolfe, Youngwood, Pa., assignors to Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Filed Sept. 25, 1967, Ser. No. 670,309 Int. Cl. F24c 3/10; F23q 3/00; H01t 13/40 U.S. Cl. 12639 17 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a means and method for igniting the pilot burner means of a cooking apparatus or the like by altering the stresses in piezoelectric crystal means to create sparks adjacent the outlet means of the pilot burner means to ignite the fuel issuing therefrom, the spark ignition means being automatically and repetitively actuated a predetermined number of times once the same is rendered operative to assure full ignition of the pilot burner means.

This invention relates to improved ignition means for a cooking apparatus or the like as well as to an improved method for igniting burner means of such a cooking apparatus or the like.

It is well known that many cooking apparatus of the fuel burning variety have individual pilot burner means for each main burner thereof whether the main burner is disposed in the oven or on the top of the cooking apparatus, the pilot burners being continuously burning pilot burners and when adversely put out because of air currents or the like, the same must be re-ignited by the housewife or the like utilizing matches and the like.

However, according to the teachings of this invention, ignition means are provided for such pilot burner means wherein the housewife or the like can initiate the actuation 0f the ignition means completely remote from the pilot burner means while igniting the pilot burner means in a simple, effective and-substantially fool-proof manner.

In particular, the ignition means of this invention includes piezoelectric crystal means that when actuated by the housewife or the like will have the stresses therein altered in such a manner that the same will cause sparking at the pilot burner means to ignite the same, the actuation of the ignition means being automatically repetitive for a predetermined period of time once the housewife or the like has initiated an ignition cycle for the apparatus in a manner hereinafter described.

Accordingly, it is an object of this invention to provide an improved ignition means for a cooking apparatus or the like, the ignition means of this invention having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved method for igniting burner means of a cooking apparatus 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:

FIGURE 1 is a perspective view of a cooking apparatus utilizing the ignition means of this invention.

FIGURE 2 is a schematic view illustrating the ignition system for the cooking apparatus of FIGURE 1.

FIGURE 3 is a fragmentary view similar to FIGURE 2 and illustrates another embodiment of this invention.

While the various features of this invention are hereinafter described and illustrated as being particularly 3,490,434 Patented Jan. 20, 1970 adaptable for providing ignition means for a cooking apparatus, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide ignition means for other apparatus as desired.

Therefore, this invention is not to be limited to only the embodiment 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 FIGURE 1, a cooking apparatus is generally indicated by the reference numeral 10 and has an oven chamber 11 provided with a broil burner 12 and a bake burner 13 illustrated in FIGURE 1 in substantial- 1y rectangular form while being illustrated in FIGURE 2 as being in tubular form. The oven chamber 11 is opened and closed by a conventional door means 14.

The cooking apparatus 10 includes a plurality of top burner means 15, 16, 17 and 18 with only the top burner means 15 and 16 being illustrated schematically in FIG- URE 2.

Individual pilot burner means are provided for the main burners of the cooking apparatus 10 and the broil pilot burner is generally indicated by the reference numeral 19, the bake pilot burner by the reference numeral 20 and the top pilot burners are generally indicated by the

reference numerals

21, 22, 23 and 24 for the respective

top burners

15, 16, 17 and 18. The

pilot burners

19, 20, 21 and 22 are illustrated schematically in FIGURE 2 and are so cOnstructed and arranged that the same are adapted to ignite fuel issuing from the respective main burner means 12, 13, 15 and 16 as long as the respective pilot burners are burning.

However, should one or more of the pilot burners of the cooking apparatus 10 be extinguished for any reas n, spark igniting means of this invention is provided for the apparatus and is generally indicated by the reference numeral 25 in FIGURES 1 and 2 and will now be described.

The spark igniting means 25 comprises a support or frame member 26 suitably mounted to the frame structure 27 of the cooking apparatus 10 in desired l cation with an on-off member 28 thereof being exposed in any suitable location on the apparatus 10, the embodiment of the igniter means 25 illustrated in FIGURE 1 having the on-off member 28 located on the control panel means 29 of the apparatus 10.

The support frame 26 has one or more piezoelectric crystal elements carried therein between the opposed ends 30 and 31 thereof with such crystal means being disposed ina recess or cutout 32 of the support frame 26. In the embodiment of the igniter means 25 illustrated in FIG- URE 2, two such piezoelectric crystal elements 33 and 34 are being utilized.

The crystal elements 33 and 34 are disposed in longitudinal stacked and aligned relation with the element 33 having electrical terminal means 35 and 36 at the opposed ends thereof and the crystal element 34 having electric-a1 terminal means 37 and 38 at the opposed ends thereof. An electrical insulator 39 is disposed between the terminal means 36 and 37 of the crystal elements 33 and 34 to effectively electrically insulate the elements 33 and 34 from each other while electrical insulating means 40 and 41 respectively electrically insulate the other ends of the crystal elements 33 and 34 from the support frame 26 whereby the crystal elements 33 and 34 are not only electrically insulated from each other, but are also electrically insulated from the support frame 26 and, thus, from the frame means 27 of cooking apparatus 10. If desired, ceramic pressure pads or

elements

42 and 43 can be re spectively disposed between the

insulators

40 and 41 and the respective terminal means 35 and 38 as illustrated.

A rocker arm 44 is pivotally or rotatably carried by the support frame 26 and is adapted to rotate relative thereto about a transversely movable axis of rotation generally indicated by the reference numeral 45, the rocker arm 44 carrying a cam member 46 at the rotatably mounted end 47 thereof to be disposed betweenthe insulator 40 and a flat surface 48 of the support frame 26 at the end 30 thereof to also rotate in unison the rocker arm 44 about the movable axis 45. The cam member 46 has a flat surface 49 cooperating with the flat surface 48 of the support frame 26 and a true, partial circular surface 50 cooperating with an adjacent flat surface 51 of the insulator 40 whereby when the cam member 46 is disposed in the position illustrated in FIGURE 2, the

elements

40, 42, 33, 39, 34, 43 and 41 are disposed in stacked relation between the opposed ends 30 and 31 of the support frame 26 and will not alter the stresses in the crystal elements 33 and 34 to generate a potential difference at the respective terminal means 35, 36 and 37, 38 until the cam element 46 is rotated about the axis 45 to either axially squeeze the elements 33 and 34 between the opposed end thereof or relieve such squeezing action. 4

In particular, when an ignition cycle is initiated by pushing in on the on-off member 28 in a manner hereinafter described, the rocker arm 44 is initially moved in a counterclockwise direction to cause the cam element 46 to rotate about its axis 45 in a counterclockwise direction. In this manner the corner 52 of the cam element 46, formed by the juncture of the flat surface 49 thereof and the circular surface 50 thereof, will bear against the flat surface 48 of the support frame 26 and cause the axis 45 to move downwardly and to the right in FIGURE 2 to increase the effective length of the cam member 46 between the surface 48 of the support frame 26 and the surface 51 of the insulator 40 to impose a substantially, longitudinal compressive and squeezing action on the elements 33 and 34 between the ends 30 and 31 of the support frame 26 so that the stresses in the crystals 33 and 34 are sufficiently altered to cause the same to create a potential difference at the respective pairs of

terminals

35, 36 and 37, 38 to be utilized in a manner hereinafter described. When such compression or squeezing action on the crystal means 33 and 34 is subsequently relieved by the rocker arm 44 being moved back in a clockwise direction in a manner hereinafter described, the cam member 46 will rock back to the position illustrated in FIGURE 2 to effectively decrease the effective cam length of the cam member 46 between the

surfaces

48 and 51 to thereby again alter the stresses in the crystal elements 33 and 34 as the same longitudinally expand from their previous squeezed condition to also generate a potential difference at the respective pairs of

terminals

35, 36 and 37, 38.

During such rotation of the cam element 46, the stack of

elements

40, 42, 33, 39, 34, 43 and 41 tends to rock as a unit to the right as the cam element 46 is rotated in a counterclockwise direction and tends to rock to the left when the cam element 46 is rotated in a clockwise direction back to the position illustrated in FIGURE 2 whereby the insulator 41 can be provided with an arcuate surface 53 that bears against a flat surface 54 of the support frame 26 to permit such rocking of the stack of elements between the opposed ends 30 and 31 of the support frame 26.

A first pair of electrodes 55 and 56 are mounted to the frame means 27 of the apparatus adjacent the

respective pilot burners

21 and 22 and in spaced relation from the

pilot burners

21 and 22 so as to define spark gaps 57 and 58 adjacent the fuel outlet means 59 and 60 of the

pilot burners

21 and 22. The electrodes 55 and 56 are electrically insulated from the frame means 27 of the apparatus 10 and are electrically interconnected to the

terminals

36 and 35 by suitable leads 61 and 62.

Similarly, another pair of

electrodes

63 and 64 are carried by the apparatus 10 and are disposed in spaced relation from

thepilot burners

19 and 20 to define

spark gaps

65 and 66 adjacent the fuel outlet ends 67 and 68 of the respective pilot burner means 19 and 20. The

electrodes

63 and 64 are also electrically insulated from the frame means 27 of the apparatus 10 and are respectively interconnected to the terminal means 38 and 37 by leads 69 and 70.

The pilot burner means 21, 22, 19 and 20 are electrically conductive and are, in effect, connected to a ground potential by being electrically interconnected to the frame means 27 of the apparatus 10 and such ground potential of the pilot burners is generally indicated by the

reference numerals

71 and 72 in FIGURE 2, the frame means 27 of the apparatus 10 being effectively grounded through interconnection thereof to the gas supply lines and the like and also by conventional grounding means.

In this manner, it can be seen that the pilot burner means 21 and 22 respectively provide ground electrodes cooperating with the electrodes 55 and 56 to define the spark gaps 57 and 58. Similarly, the

pilot burners

19 and 20 provide ground electrodes for cooperating with the elec- 27 of the apparatus 10 and carrying a flexible diaphragm 75 that closes its opened end and defines a chamber 77 therewith. The flexible diaphragm 76 is normally urged to the position illustrated in FIGURE 2 by a compression spring 78 disposed within the chamber 77 of the actuator 74 whereby when the chamber 77 of the actuator 74 is at atmospheric conditions, the rocker arm 44 tends to assume the position illustrated in FIGURE 2, because the flexible diaphragm 76 is interconnected to the rocker arm 44 by an actuating post means 79 secured to the diaphragm 76 and pivotally interconnected to the right hand end 80 of the rocker arm 44 by pivot pin means 81. However, when a vacuum is created in the chamber 77 of the actuator 74, the diaphragm 76 is pulled upwardly in FIG- URE 2 to rock the rocker arm 44 in a counterclockwise direction.

A vacuum source 82, such as a vacuum pump or the like, has its inlet interconnected to a conduit means 83 that leads to the chamber 77 of the actuator 74, the conduit means 83 having a timer controlled valve means 84 therein intermediate the actuator 74 and the vacuum source 82 to alternately interconnect the two

branches

83A and 83B of the conduit means 83 together and to disconnect the

conduit sections

83A and 83B from each other while interconnecting the conduit section 83B to the atmosphere.

In this manner, the timer operated valve means 84, when initially actuated by the housewife or the like pushing in on the push button or selector means 28, will automatically cycle through its operating positions a predetermined number of times to alternately interconnect the chamber 77 of the actuator 74 to the vacuum source 82 and cause the rocker arm 44 to pivot in a counterclockwise direction and to disconnect the chamber 77 of the actuator 74 from the vacuum source 82 and interconnect the same to the atmosphere so that the actuator 74 will move the rocker arm 44 in a clockwise direction back to the position illustrated in FIGURE 2. Thus, the rocker arm 44 will be repetitively moved in a counterclockwise and in a clockwise direction a predetermined number of times once the timer operated valve means 84 is rendered operative, the timer operated valve means 84 automatically turning itself off after a predetermined time period has lapsed after the same has been initially rendered operative by the housewife or the like pushing in on the onoif member 28.

The operation of the igniting means 25 for the appara tus 10 will now be described.

When the housewife or the like notices that one of the burner means 12, 13, 15, 16, 17 or 18 does not ignite when she turns on one of the main selector knobs 73 on the control panel 29 of the apparatus 10, or when she actually notices that one or more of the pilot burner means 19, 20, 21, 22, 23 and 24 are not burning, she can merely push inwardly on the push button 28 to effect repetitive rocking of the cam member 46 of the igniter means 25 by, the repetitive actuation and deactuation of the actuator 74 in the manner previously described.

Af s' the rocker arm 44 is being moved in a counterclockwise direction by the actuation of the actuator 74, the stresses in each crystal element 33 and 34 will be altered in the manner previously described so that one potential will be created at the electrodes 55 and 63 and an equal and opposite potential will be created at the

electrodes

56 and 64. When the differences in potential between the

electrodes

55, 56, 63 and 64 and their respective grounded

electrodes

21, 22, 19 and 20 reaches a particular magnitude, electrical arcing will be created across the

spark gaps

57, 58, 65 and 66 in substantially a simultaneous manner whereby such electrical sparking will ignite the fuel issuing from any unlit pilot burner means 21, 22, 19 or 20.

Continued upward movement of the diaphragm 76 of the actuated actuator will effect a squeezing action on the elements 33 and 34 that will produce the above-described sparking one or more times depending upon the length of upward movement of the diaphragm. Also, subsequent deactuation of the actuator 74 by the timer operated valve means 84 will also alter the stresses in the crystals 33 and 34 to effect sparking at the

spark gaps

57, 58, 65 and 66 on the return of the diaphragm 76 to its full down position as illustrated in FIGURE 2.

While it is believed that merely one actuation and deacttiation of the actuator 74 will effectively light any unlit pilot 'burnermeans 19-22, the repetitive and automatic cycling of the actuator 74 by the timer means 84 for a predetermined period of time will more than assure that anyunlit pilot burner means 19-22 will be effectively lit by the repetitive sparking created by the crystal means 33 and 34 once an ignition cycle has been initiated.

Therefore, it can be seen that by arranging the crystal means 33 and 34 in the manner previously described, each crystal means 33 or 34 is adapted to effectively ignite two or more pilot burner means so that a relatively inexpensive ignition means can be provided for the apparatus 10.

While the igniter means 25 illustrated in FIGURE 2 has the crystal element 34 being utilized to ignite the oven pilot burner means 19 and 20 and the crystal element 33 to ignite only the pilot burner means 21 and 22 of the top burner means 15 and 16, it is'to be understood that a third crystal element can be disposed in a stacked relation in a manner similar to that illustrated in the drawings to effect sparking at the pilot burner means 23 and 24 of the other top burners 17 and 18.

However, it is also to be realized that the pilot burner means 21 and 22 illustrated in FIGURE 2 could be utilized as the only top pilot burner means for the apparatus and the same could be utilized in combination with flash tubes so that the pilot burner means 21 can effectively ignite the two top burner means and 16 and the pilot burner means 22, through another flash tube arrangement, can be utilized to ignite the other two burner means 17 and 18 in a manner well known in the art. Thus, it is believed that only two piezoelectric crystals are necessary for effectively igniting all of the required number of pilot burner means for a cooking apparatus of the type similar to the apparatus 10 illustrated in FIGURE 1.

While the repetitive and automatic actuation of the ignition means 25 has been previously described as being produced by pneumatically operated means, it is to be understood that such repetitive and automaticoperation can be accomplished by other cycling means as desired.

For example, another embodiment of the ignition means of this invention is generally indicated by the reference numeral 25A in FIGURE 3 and parts thereof similar to the ignition means 25 of FIGURE 2 are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIGURE 3, the on-off member 28A is adapted to operate a suitable electric timer 85 which will interconnect the power source leads L and L to leads 86 and 87 leading respectively to a suitable electric motor '88. The motor 88, through suitable drive means 89, will rotate a cam member or element 90 about its axis 91 in a continuous manner as long as the timer 85 interconnects the power source leads L and L thereto.

The cam member or element 90 is adapted to have its cam surface 92 bear against the right hand end A of the rocker arm 44A to repetitively rock the rocker arm 44A in a clockwise and counterclockwise direction to respectively produce a squeezing action and a relieving action on the piezoelectric crystal means of the ignition means 25A for the purpose previously described.

Thus, it can be seen that the ignition means 25A of FIGURE 3 operates in substantially the same manner as the ignition means 25 of FIGURE 2 previously described except that the timer means will interconnect electrical current to the electric motor 88 for a predetermined period of time once the timer means 85 has been actuated by the housewife or the like pushing in on the on-off member 28A whereby the continuous operation of the motor 88 during the predetermined time period will cause repetitive rocking of the rocker arm 44A to produce sparking at the pilot burner means in the manner previously described during that predetermined period of time to assure full ignition of all pilot burner means.

Also, while this igniter means of this invention has been described as igniting pilot burner means for the cooking apparatus, it is to be understood that such igniter means can be utilized to directly ignite the main burner means of the cooking apparatus or the like without utilizing pilot burners therefor.

While the form of the invention now preferred has been disclosed as required by the statutes, other forms may be used, all coming within the scope of the claims which follow.

We claim:

1. In a cooking apparatus having burner means, igniting means for said burner means, said igniting means having piezoelectric crystal means for creating sparks to ignite said burner means when the stresses of said crystal means are altered a certain amount, pneumatically operated actuating means for altering said stresses to cause said sparks each time said actuating means is actuated, and cycling means for repetitively actuating and deactuating said pneumatically operated actuating means a predetermined number of times each time said cycling means is rendered operative.

2. In a cooking apparatus as set forth in claim 1, said burner means comprising a plurality of burners that are each adapted to be ignited by said sparks in substantially a simultaneous manner.

3. In a cooking apparatus as set forth in claim 1, said burner means comprising pilot burner means for igniting main burner means of said cooking apparatus.

4. In a cooking apparatus as set forth in claim 3, said pilot burner means comprising a plurality of pilot burners that are each adapted to be ignited in substantially a simultaneous manner by said sparks.

5. In a cooking apparatus as set forth in claim 1, said cycling means comprising a timer means.

6. In a cooking apparatus having burners means, igniting means for said burner means, said igniting means having piezoelectric crystal means for creating sparks to ignite said burner means when the stresses of said crystal means are altered a certain amount, actuating means for altering said stresses to cause said sparks each time said actuating means is actuated, cycling means for repetitively actuating said actuating means a predetermined number of times each time said cycling means is rendered operative, said actuator means comprising a pneumatically operated actuator, and a pneumatic source for actuating said actuator when fluidly interconnected thereto, said actuator being deactuated when disconnected from said source, said cycling means alternately connecting and disconnecting said source to and from said actuator to repetitively actuate said actuator.

7. In a cooking apparatus having burner means, igniting means for said burner means, said igniting means having piezoelectric crystal means for creating sparks to ignite said burner means when the stresses of said crystal means are altered a certain amount, actuating means for altering said stresses to cause said sparks each time said actuating means is actuated, cycling means for repetitively actuating said actuating means a predetermined number of times each time said cycling means is rendered operative, said actuator means comprising an electrically operated actuator, an electrical power source, said actuator comprising an electrical motor, and a cam means driven thereby, whereby movement of said cam causes altering of said stresses in said crystal means, said cycling means interconnecting said source to said motor for a predetermined length of time when said cycling means is rendered operative to cause continuous movement of said cam means during said predetermined period of time.

8. In a cooking apparatus as set forth in claim 1, said crystal means comprising a plurality of piezoelectric crystals each being stressed by said actuator means.

9. A method for igniting burner means of a cooking apparatus comprising the steps of altering the stresses in piezoelectric crystal means with pneumatically operated actuator means to create sparks to ignite said burner means when the stresses of said crystal means are altered a certain amount, repetitively actuating and deactuating said pneumatically operated actuator means a predetermined number of times with a cycling means each time said cycling means is rendered operative, and initiating the operation of said cycling means so that said burner means will be sparked a plurality of times in an automatic manner to substantially insure that said burner means will be ignited.

10. A method as set forth in claim 9 wherein said burner means comprises a plurality of burners and wherein said step of creating said sparks includes the step of creating sufficient sparks for igniting all of said burners in a substantially simultaneous manner.

11. A method as set forth in claim 9 wherein said burner means comprises a pilot burner means, and including the step of igniting main burner means of said ap aratus with said pilot burner means after said pilot burner means is ignited by said sparks.

12. A method as set forth in claim 11 wherein said pilot burner means comprises a plurality of pilot burners and wherein said step of creating said sparks includes the step of creating sufficient sparks for igniting all of said said crystal meansare altered a certain amount, repetitively actuating said actuator means a predetermined number of times with a cycling means each time said cycling means is rendered operative, and initiating the operation of said cycling means so that said burner means will be sparked a plurality of times in an automatic manner to substantially insure that said burner means will be ignited, said actuator means comprising a pneumatically operated actuator and said step of repetitively actuating said actuator comprising the step of repetitively and pneumatically operating said actuator, said last-named step comprising the step of repetitively interconnecting and disconnecting said actuator from a pneumatic source with said cycling means.

15. A method for igniting burner means of a cooking apparatus comprising the steps of altering the stresses in piezoelectric crystal means with actuator means to create sparks to ignite said burner means when the stresses of said crystal means are altered a certain amount, repetitively actuating said actuator means a predetermined number of times with a cycling means each time said cycling means is rendered operative, and initiating the operation of said cycling means so that said burner of repetitively actuating said actuator includes the step of interconnecting said motor to an electrical power source for a predetermined length of time by said cycling means to cause continuous movement of said cam means during said predetermined period of time.

17. A method as set forth in claim 9 wherein said crystal means comprises a plurality of crystal elements and wherein said step of altering said stresses includes the step of altering the stresses of all of said crystal elements by said actuator means in a substantial simultaneous manner.

References Cited UNITED STATES PATENTS 2,513,257 6/1950, Strobel 431-45 3,136,355 7/1964 Weber 43l255 X 3,344,835 10/1967 Hodgson 431--255 EDWARD G. FAVORS, Primary Examiner US. Cl. X.R.