Piezo-electric Ignition Device For Gas Appliances And The Like

Abstract

A device for causing piezoelectric spark ignition of gas in gas stoves, appliances, and the like. The device is easily assembled and holds the piezoelectric element and lead wires securely in place.

Description

DESCRIPTION OF THE INVENTION

This invention relates generally to piezoelectric devices and more particularly concerns piezoelectric devices which may be used to generate electric sparking currents.

It is the primary aim of this invention to provide a piezoelectric spark-producing device for the ignition of gas in gas appliances and the like, the device being characterized by durability and simplicity of manufacture.

It is another object of the invention to provide a device for the ignition of gas in gas applicances and the like, wherein the piezoelectric generation of an igniting spark is positively assured each time the device is used. In this connection, a related object is to provide a piezoelectric device wherein the piezoelectric element is positively maintained in its correct position even when jarred by the blow of a trigger hammer.

It is a further object of the invention to provide a piezoelectric device wherein the durable connection of a lead wire to the device is assured.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:

FIG. 1 is a plan view of a piezoelectric unit, having a lead wire attached thereto;

FIG. 2 is a cross-sectional view, taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged view of the right end portion of FIG. 2;

FIG. 4 is a perspective exploded view of the parts shown in FIG. 3;

FIG. 5 is a perspective exploded view of the piezoelectric unit and its enclosing case, together with supporting parts;

FIG. 6 is a perspective view showing the parts of FIG. 5 in their assembled positions;

FIG. 7 is a plan view showing the assembled device of FIG. 6;

FIG. 8 is a perspective exploded view showing the assembly of FIGS. 6 and 7 in combination with an actuating mechanism;

FIG. 9 is a perspective view showing the parts of FIG. 8 in their assembled positions, but with the case cover removed; and

FIG. 10 is a perspective view showing the device in its completely assembled form.

While the invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment. On the contrary, I intend to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.

Turning now to the drawings and referring first to FIGS. 1 and 2, there is shown a spark-generating unit 10 including a piezoelectric element 11 for producing electrical pulses in an output wire 12 in response to mechanical impulses applied to an input member 13. The electrical pulses are conducted by the wire 12 to an electrode pair (not shown) to produce an arc sufficient to ignite the gas fuel in a gas appliance or the like. To generate the electrical pulses, a striking mechanism to be described below strikes the input member 13, which is bonded to the casing 14 by a resilient seal 15, thereby applying pulse-generating impulses to the end of the piezoelectric element 11 contained within the casing 14.

In accordance with one important aspect of the present invention, a conductive element is mechanically coupled to the piezoelectric element for receiving the electrical pulses, and the output wire is electrically connected to the conductive element, with the output wire and the conductive element being mounted for limited movement relative to each other while maintaining electrical contact therewith. Thus, in the illustrative embodiment, the pulses generated by the piezoelectric element 11 are transmitted to a conductive annulus 20 via a conductive base member 21 disposed between the element 11 and the annulus 20. From the annulus 20, the pulses are conducted to the output wire 12, the end of which is stripped of insulation and fitted through the central aperture in the annulus 20 so as to be in sliding contact therewith. To permit some small relative movement between the annulus 20 and the wire 12, the wire 12 is not rigidly connected to the annulus 20, but rather extends through rough the annulus 20 into a cavity 21a formed by the end portion of the base member 21. Within the cavity 21a, the end of the wire 12 is secured to a terminal member 22, which is larger than the hole in the annulus 20. Thus, should the wire 12 be accidentally or otherwise tugged upon, it will not lose electrical contact with or break away from the unit 10 or its parts.

Thus, a mechanical impulse or blow delivered to the input member 13 results in an electrical impulse or spark current being sent by the wire 12 to the ignition electrode.

In order to deliver the mechanical impulse or blow properly, the spark-generating unit 10 must be accurately positioned with respect to the striking mechanism and other parts. For this reason, the spark unit 10 is carried upon a frame 25, as seen in FIGS. 5--7.

In accordance with the invention, a support plate 26 forms a socket 27 which engages the spark unit 10. Legs 28, 29 are provided on the plate 26 and are fitted into slots 30, 31 formed in the frame 25. One slot 31 is longer than the other slot 30 to allow the legs 28, 29 to be slipped thereinto; the plate 26 can thus be engaged with the frame 25 by a simple twisting motion. More particularly, the plate 26 is disposed with the leg 28 in the short slot 30 and the leg 29 at the forward end of the long slot 31, i.e., the end toward the input end of the spark unit 10, and then the plate is pivoted about the leg 28 so that the leg 29 slides rearwardly into the slot 31, thereby positioning the plate 26 within the frame 25. As one particular feature of the invention, the legs 29 and 28 engage arcuate bearing surfaces 32 and 33 formed by the frame 25 at the rear ends of the slots 31 and 30, respectively.

Still another important aspect of the invention is found in the resilient U-shaped retainer 35, the legs 36, 37 of which are provided with coaxial holes to engage the input member 13 of the spark unit 10. The forward leg 37 of the retainer 35 engages detents 38, 39 formed on the frame 25; the rear leg 36 abuts the unit 10. The retainer 35 is formed of a resilient material, such as common sprig steel, so as to force the unit 10 to snugly engage the rear support plate 26, and to absorb mechanical impulse vibrations rather than transmit them to the frame 25.

Thus the spark-generating unit 10 may be easily assembled into the frame 25, and is accurately positioned therein, while the frame is insulated from the impulses delivered to the unit.

To generate the blows or mechanical impulses, the actuating and hammer assembly illustrated in FIGS. 8--10 is provided. When an actuator 41 is rotated as indicated in FIG. 10, the attached pivots 42 rotate, and force a slide plate 43 to move, in the illustration downward and to the left, over a cover 44 on the top of the frame 25. A finger 46, depending from the slide 43, engages a hammer 47 and forces it against a spring 48. When the feet 49 encounter the oblique or inclined portion 51 formed upon the frame 25 the feet 49 ride up thereupon, and retract the finger 46 from engagement with the hammer 47. The hammer then springs forward, delivering the requisite impulse or blow to the spark-generating unit. When the actuator 41 is released, a small normally bent spring 52 forces the slide plate 43 and attached actuator 41 to return to their original positions, and the finger 46, obliquely formed on the slide plate 43, reengages the hammer 47.

Thus, by rotation of the actuator 41, a blow is delivered to the spark-generating unit 10, and a gas-igniting spark is generated.

Claims

I claim:

1. A piezoelectric spark-generating device for use as an ignition device in gas appliances and the like, said device comprising the combination of

a piezoelectric element,

means for subjecting said piezoelectric element to mechanical impulses to produce corresponding electrical pulses,

an annular electrically conductive element electrically coupled to said piezoelectric element for receiving said electrical pulses,

a conductive base member disposed between said piezoelectric element and the annular conductive element, the end portion of said base member forming a cavity adjacent to the central portion of said annular element,

an electrically conductive wire passing through the annular element and having an end located within the cavity, and

a terminal member secured to the wire end and located within the cavity, so as to permit limited movement of the terminal member and wire end within the cavity while permitting firm bearing engagement between the conductive base element and annular element.

2. A piezoelectric spark-generating device for use as an ignition device in gas appliances and the like, said device comprising the combination of

a casing,

a piezoelectric element enclosed within the casing for producing electrical pulses in response to mechanical impulses delivered to the element,

means for generating mechanical impulses in a predetermined direction,

an input member mounted upon the casing and operatively connected to the means for generating mechanical impulses for subjecting the piezoelectric member to the generated mechanical impulses delivered in said determined direction,

an attaching member securing the input member to the casing,

an electrically conductive element mechanically coupled to said piezoelectric element for receiving said electric pulses,

an electrical conductor electrically connected to said conductive element, extending through the conductive element in said predetermined direction, and mounted for movement relative to said conductive element in said predetermined direction while maintaining said electrical connection.

3. A piezoelectric spark-generating device for use as an ignition device in gas appliances and the like, said device comprising the combination of

a casing,

a piezoelectric element enclosed within the casing,

means for generating mechanical impulses,

an input member mounted upon the casing and operatively connected to said means for generating mechanical impulses and the piezoelectric member, so as to subject the piezoelectric member to the generated mechanical impulses and produce corresponding electrical pulses,

a seal member bonding the input member to the casing,

an annular electrically conductive element mechanically coupled to said piezoelectric element for receiving said electrical impulses,

an electrically conductive wire passed through a hole in an end wall of said casing and through the central opening of the annulus, the wire being mounted for sliding contact with the annular element, and

a terminal member larger than the annular hole, fixed to the wire and located beyond the annulus and the conductive element so as to prevent withdrawal of the wire from the annulus while permitting limited relative movement between said annulus and said wire.