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Publication numberUS3544819 A
Publication typeGrant
Publication dateDec 1, 1970
Filing dateJul 19, 1968
Priority dateJul 19, 1968
Publication numberUS 3544819 A, US 3544819A, US-A-3544819, US3544819 A, US3544819A
InventorsGood Arthur L
Original AssigneeRobertshaw Controls Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Ignition means for a cooking apparatus or the like
US 3544819 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Dec. 1, 1970 A. 1.. GOOD 3,544,819

I IGNITION MEANS FOR A COOKING APPARATUS OR TI- IE LIKE I Filed July 19, 1968 2 Sheets-Sheet 1 I IO II INVENTOR. ARTHUR L. 6000 HlS ATTORNEYS I Y1 FI,G.2 F|G.3 v i wn I Dec. 1, 1970 5000 3,544,819

' IGNITION MEANS FOR A COOKING APPARATUS OR THE LIKE Filed July 19, 1968 I 2 Sheets-Sheet 2 INVENTOR. ARTHUR L. GOOD HIS ATTORNEYS United States Patent Oflice 3,544,819 Patented Dec. 1, 1970 3,544,819 IGNITION MEANS FOR A COOKING APPARATUS OR THE LIKE Arthur L. Good, Elkhart, Ind., assignor to Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Filed July 19, 1968, Ser. No. 746,049 Int. Cl. H01v 7/00 US. Cl. 3108.7 12 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to an improved means for altering the stresses in piezoelectric crystal means for spark igniting purposes and the like, the stresses in the crystal means being altered by an electromagnetic motor means having its armature balanced between the force of a spring means and the compressive force of the crystal means being operatively interconnected to one end of the armature by a lever means pivotally mounted between the ends thereof.

This invention relates to improved apparatus for altering the stresses in a piezoelectric crystal means to cause sparking for ignition purposes or the like.

It is well known that piezoelectric crystal means can have the internal stresses therein altered in a manner to produce an electrical potential at an electrode interconnected to such crystal means whereby when the magnitude of the potential differential between that electrode and another electrode reaches a predetermined point, sparking is created across the spark gap between such electrodes and such sparking can be utilized to ignite the gaseous fuel and the like issuing from a burner means disposed closely adjacent the spark gap.

Therefore, it is a feature of this invention to provide improved means for altering the stresses of such a crystal means.

In particular, the illustrated embodiment of this invention has an electromagnetic motor means operatively interconnected to the piezoelectric crystal means to alter the stresses therein, the electromagnetic motor including a movable armature having one end disposed against one end of a lever pivotally mounted to frame means carrying the crystal means in such a manner that the other end of the lever bears against one end means of the crystal means. A spring means is carried by the frame means and bears against the other end of the armature so that the spring means always maintains a preload on the crystal means which has the stresses therein altered by the subsequent energizing of the coil means of the motor means to cause reciprocating movement of the armature.

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

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, partially in cross-section, illustrating the ignition means of this invention.

FIG. 2 is a left-hand end view of the actuator of FIG. 1.

FIG. 3 is a right-hand end view of the actuator of FIG. 1.

FIG. 4 is an exploded perspective view of various parts of the actuator of FIG. 1.

While the various features of this invention are hereinafter described and illustrated as being particularly adapted to provide sparking for igniting burner means 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 means for altering the stresses in piezoelectric crystal means for any desired purpose.

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 FIG. 1, the improved ignition means of this invention is generally indicated by the reference numeral 10 and comprises a support frame 11 carrying a piezoelectric crystal means or stack, generally indicated by the reference numeral 12, disposed within a cutout or slot 13 formed therein and utilized for creating an electrical potential at an electrode 14 that is spaced from a grounded pilot burner means 15 that defines a spark gap 16 therewith. In this manner, the stresses in the piezoelectric crystal means 17 of the crystal stack 12 can be altered in a manner hereinafter described and when the potential difference between the electrodes 14 and 15 reaches a certain magnitude, electrical sparking is created across the spark gap 16 to ignite fuel issuing from an outlet means 18 of the pilot burner means 15, the ignited pilot burner means 15 now being adapted to ignite fuel issuing from a main burner means 19 of the cooking apparatus or the like disposed adjacent thereto.

The crystal stack 12 comprises a cylindrical member 20 having opposed open ends 21 and 22 and carrying the piezoelectric crystal means 17 therein. A pair of pressure pads 23 and 24 are respectively received in the opposed open ends 21 and 22 of the cylindrical member 20 to respectively engage the opposed ends 25 and 26 of the crystal means 17 to help support the crystal means 17 within the cylinder member 20.

As illustrated in FIG. 4, the cutout 13 in the frame 11 defines opposed arcuate surfaces 27 and 28 which are respectively received in annular recesses 29 and 30 formed respectively in roller means 31 and 32 that are respectively engaged by the pressure pads 23 and 24 as illustrated in FIG. 1. In this manner, the elements 31, 23, 17, 24 and 32 are disposed in stacked aligned relation between the opposed arcuate surfaces 27 and 28 of the frame 11.

A movable member or lever means 33 is pivotally carried by the frame means 11, the movable member or lever means 33 comprising two like parts 34 and 34 fastened together in spaced relation by rivetlike means 35, FIG. 2, so as to operate in unison.

The lever means 33 is pivotally mounted to the frame means 11 by a pivot pin 36 disposed intermediate the opposed ends 37 and 38 of the lever means 33, the end 37 of the lever means 33 having an arcuate surface 39 engaging against the roller means 31 as illustrated in FIG. 1. The other end 38 of the lever means 33 is disposed in abutting relation and end means 40 of a movable armature 41 of an electromagnetic motor 42 suitably carried by the frame means 11 in any suitable manner.

The motor means 42 can comprise a conventional AC electromagnetic coil means 43 with the shading rings removed and telescopically receiving the movable arma ture 41 therethrough whereby the previously described end means 40 of the armature 41 projects to the left beyond the coil means 43 and the other end 44 of the armature 41 projects to the right out of the core means 43 and has shoulder means 45 for limiting movement of the armature 44 to the left in 'FIG. 1 when the coil 43 is energized as the shoulder means 45 will abut against the coil support 46.

The frame 11 has a tongue portion 47 projecting to the right thereof in FIG. 1 with a reversely turned tang 48 at the upper end thereof.

A leaf-like spring 49 is best illustrated in FIG. 4 and has an elongated slot 50 passing therethrough intermediate opposed bowed ends 51 and 52 thereof. The slot 50 of the spring 49 permits the spring 49 to be assembled on the tongue portion 47 of the frame 11 in a telescoping manner as illustrated in FIG. 1 and then be moved vertically downwardly so that the tang 48 bears against a nonslotted portion of the leaf spring 49 as illustrated in FIG. 3. When the spring 49 is assembled in this manner, the lower end 52 thereof bears against the right-hand end 44 of the armature 41 and the upper end 51 of the spring 49 bears against a permanently deformable part 53 of the frame 11 as illustrated in FIG. 1.

In this manner, the deformable part 53 can be permanently deformed relative to the remainder of the frame 11 so as to provide the desired degree of bowness of the leaf spring 49 about the abutment or tang 48 of the frame 11 so that the spring 49 will tend to move the armature 44- to the left in FIG. 1 with a predetermined force resisted only by the crystal means 17 that is, thus, being compressed by the lever or movable member 33 tending to be moved in a clockwise direction by the spring 49.

Therefore, it can be seen that in the position of FIG. 1, the armature 44 is balanced between the force of the leaf spring 49 tending to move the same to the left in FIG. 1 and the resisting compression force of the crystal means 17 tending to pivot the lever 33 in a counterclockwise direction. Accordingly, the crystal means 17 not only always has a preloading force thereon provided by the spring means 49', but also such preloading force maintains the elements 31, 23, 17, 24 and 32 in stacked compressed relation.

From the above, it can be seen that the ignition means of this invention can be formed of a relatively few parts that can be manufactured and assembled together in a relatively simple manner to be utilized for ignition purposes in a manner now to be described.

When the housewife or the like desires to turn on the main burner means 19 of the cooking apparatus by operating the respective selector knob therefor (not shown) and the burner means 19 does not ignite because of the pilot burner means being unlit, or when she actually notices that the pilot burner means 15 has been extinguished for some reason, the housewife or the like can effect the ignition of the pilot burner means 15 by causing the electromagnetic motor means 42 to repetitively pivot the movable member lever means 33 first in a clockwise direction in FIG. 1 and then backwards in a counterclockwise direction one or more times as desired or as automatically determined by suitable timer means.

In particular, the housewife or the like, when energizing the coil 43 of the electromagnetic motor means 42 either by manually completing an electrical circuit thereto or by causing an automatic timer means to complete the electric circuit thereto for a predetermined period of time after the lapse of which the timer means will terminate the electrical current to the coil means 43, causes the armature 41 to reciprocate relative to the coil 43 in a manner well known in the art as long as the coil is electrically interconnected to an alternating current.

In any event, the armature 41 is initially moved or drawn to the left in FIG. 1 by one cycle of the energized coil means 43 to cause the lever means 33 to pivot in a clockwise direction whereby the arcuate surface 39 on the end 37 of the lever means 33 acts against the roller means 31 to longitudinally compress the crystal means 17 between the pressure pads 23 and 24 to alter the stresses therein in such a manner that the resulting potential now being created at the electrode 14 will cause a discharge across the spark gap 16 in cooperation with the grounded pilot burner means 15 one or more times during such clockwise movement of the lever means 33 whereby such sparking at the spark gap 16 will ignite fuel issuing from the outlet 18 of the pilot burner means 15.

Conversely, when the next cycle of the coil means 43 ceases to pull or hold the armature 44 to the left in FIG. 1, the armature 44 is permitted to move back to the right by the force of the previously squeezed or compressed crystal means 17 which is now permitted to longitudinally expand and cause the lever means 33 to move back in a counterclockwise direction in opposition to the force of the leaf spring 49 whereby the thus expanding crystal means 17 is also having its stresses altered so that the resulting potential difference between the electrodes 14 and 15 will also cause sparking at the spark gap 16 one or more times to substantially assure that the pilot burner means 15 will be ignited.

Accordingly, it can be seen that the electromagnetic motor means 42 of this invention is utilized to effect reciprocating movement of the armature 41 and, thus, repetitive clockwise and counterclockwise movement of the lever means 43 to alternately and repetitively provide a squeezing action on the crystal means 17 and then a relieving of such squeezing action on the crystal means 17 to alter the stresses therein for the aforementioned ignition purposes as long as the coil 43 is being energized by an alternating current.

While the ignition means 10 of this invention has been previously described as being utilized in connection with a cooking apparatus, it can be seen that the ignition means 10 of this invention provides an electromechanical means of actuating the piezoelectric crystal means 17 in order to produce a high electrical potential resulting in intermittent sparking of high frequency across the spark gap 16 whereby such sparking could be considered for use in oil burner ignition systems or with any other types of volatile fuel.

Therefore, this invention not only provides an improved piezoelectric crystal actuator means, but also this invention provides improved ignition means for a burner or the like.

What is claimed is:

1. In combination, frame means, piezoelectric crystal means carried by said frame means, a movable member carried by said frame means and being operatively inter connected to said crystal means to alter the stresses therein when said member is moved in a particular direction, electromagnetic motor means carried by said frame means and being operatively interconnected to said movable member to move the same when said motor means is energized, said movable member being pivotally mounted to said frame means between opposed end means of said member, one end means of said member bearing against an adjacent end means of said crystal means and the other end means of said member bearing against said motor means, and spring means carried by said frame means and being operatively interconnected to said motor means to tend to maintain a constant load on said crystal means through said movable member.

2. A combination as set forth in claim 1 wherein said motor means has a movable armature provided with opposed end means, one of said end means of said armature being disposed against said other end means of said movable member and the other end means of said armature being engaged by said spring means whereby said spring means tends to move said armature in a direction to preload said crystal means.

3. A combination as set forth in claim 2 wherein said motor means has an electrical coil means, said armature passing through said coil means with said opposed end means thereof extending beyond the opposed end means of said coil means.

4. A combination as set forth in claim 5 wherein said spring means comprises a leaf spring that is carried by said frame means and has opposed ends, one of said ends engaging said other end means of said armature to tend to preload said crystal means with a compressive force.

5. A combination as set forth in claim 4 wherein said frame means has a tongue portion, said leaf spring having a slot passing therethrough between said opposed ends thereof and receiving said tongue portion, said tongue portion having an abutment engaging against said spring between said slot and the other end thereof, said other end of said spring abutting said frame means whereby said spring is bowed between said ends thereof by said abutment.

6. A combination as set forth in claim 5 wherein said frame means has a deformable part that is engaged by said other end of said spring to permanently adjust the bow of said spring in relation to the deforming of said part relative to said frame means.

7. In combination, a burner means for issuing fuel, electrode means associated with 'said burner means for creating electrical sparking to ignite said issuing fuel, frame means, piezoelectric crystal means carried by said frame means, means electrically interconnecting said crystal means to said electrode means, a movable member carried by said frame means and being operatively interconnected to said crystal means to alter the stresses therein and create said electrical sparking at said electrode means when said member is moved in a particular direction, electromagnetic motor means carried by said frame means and being operatively interconnected to said movable member to move the same when said motor means is energized, said movable member being pivotally mounted to said frame means between opposed end means of said member, one end means of said member bearing against an adjacent end means of said crystal means and the other end means of said member bearing against said motor means, and spring means carried by said frame means and being operatively interconnected to said motor means to tend to maintain a constant load on said crystal means through said movable member.

8. A combination as set forth in claim 7 wherein said motor means has a movable armature provided with opposed end means, one of said end means of said armature being disposed against said other end means of said movable member and the other end means of said armature being engaged by said spring means whereby said spring means tends to move said armature in a direction to preload said crystal means.

9. A combination as set forth in claim 8 wherein said motor means has an electrical coil means, said armature passing through said coil means with said opposed end means thereof extending beyond the opposed end means of said coil means.

10. A combination as set forth in claim 15 wherein said spring means comprises a leaf spring that is carried by said frame means and has opposed ends, one of said ends engaging said other end means of said armature to tend to preload said crystal means with a compressive force.

11. A combination as set forth in claim 10 wherein said frame means has a tongue portion, said leaf spring having a slot passing therethrough between said opposed ends thereof and receiving said tongue portion, said tongue portion having an abutment engaging against said spring between said slot and the other end thereof, said other end of said spring abutting said frame means whereby said spring is bowed between said ends thereof by said abutment.

12. A combination as set forth in claim 11 wherein said frame means has a deformable part that is engaged by said other end of said spring to permanently adjust the bow of said spring in relation to the deforming of said part relative to said frame means.

References Cited UNITED STATES PATENTS 3,211,949 10/1965 Slaymaker et al. 3108.3X 3,389,275 6/1968 Brothers 310-83 3,444,435 5/1969 Halm 310-81 3,462,234 8/1969 Branson et al. 431--255 FOREIGN PATENTS 1,099,969 1/1968 England 310-83 MILTON O. HIRSHFIELD, Primary Examiner M. O. BUDD, Assistant Examiner US. Cl. X.R.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3211949 *Nov 7, 1961Oct 12, 1965Clevite CorpCyclicly operating piezoelectric voltage source
US3389275 *Jan 19, 1967Jun 18, 1968Army UsaPiezoelectric generator unit for space vehicles
US3444435 *Jul 13, 1967May 13, 1969Halm RichardElectromagnetic ignition device,particularly for lighters
US3462234 *Sep 25, 1967Aug 19, 1969Robertshaw Controls CoIgnition means for cooking apparatus and the like
GB1099969A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4001615 *May 7, 1973Jan 4, 1977Berlincourt Don AElectrically actuated piezoelectric high voltage impact mechanism
Classifications
U.S. Classification310/339, 361/260, 431/255
International ClassificationF23Q3/00
Cooperative ClassificationF23Q3/002
European ClassificationF23Q3/00A