EP1747401B1

EP1747401B1 - Electronic ignitor

Info

Publication number: EP1747401B1
Application number: EP04718378A
Authority: EP
Inventors: Hamdi Erem; Nazim Sasmaz; Timur Erdogan; Murat Kumru
Original assignee: Erta Elektromekanik Imalat San Ve Tic Ltd Sti
Current assignee: Erta Elektromekanik Imalat San Ve Tic Ltd Sti
Priority date: 2004-03-08
Filing date: 2004-03-08
Publication date: 2011-06-29
Anticipated expiration: 2024-03-08
Also published as: EP1747401A1; ATE514904T1; WO2005093325A1

Abstract

An electronic ignitor for gas burners, comprising a casing (1) of insulating material and in the from of a rectangular prism having at least one open side ( D and/or F ); one or more secondary coils (3) wound around one or more bobbin carcasses placed in the first compartment (1b); a primary coil (5) nested in said secondary coil (s) (3); a plate (6) placedd in the second compartment (1a) for carrying several electronic components such as ground and supply terminals (10,11,and 12) wherein said bobbin carcass (3) involves integrally formed ducts (3a) to house output terminals (4) connected to the secondary coil.

Description

Technical Field

This invention relates to an improved electronic ignitor for gas burners, which provides a cheap and quick assembly of its components as wells as a more functional and quick mounting of the electronic ignitor to the appliance.

Background Art

It is well known in the art to make use of pushbutton-controlled electronic ignitors for lighting gas burners of various appliances such as cooking ranges. Those ignitors comprise a circuit, which is connected to at least one output terminal. Each of said output terminals, in turn, is electrically connected to an electrode placed in the close vicinity of the burner. The current discharge generated in the circuit creates a high-voltage spark between the electrode and the burner, in order to light the gas.
The first known electronic ignitor comprises a two-compartment insulating casing; primary and secondary coils placed in one compartment of said casing, and a plate in the other compartment for carrying several electronic parts of the circuit. The secondary coils are connected to output terminals and the supply terminals are connected to the plate, which is in turn connected to the primary coil. The casing involves integral ducts opening at their one end to the respective compartments, into which output and supply terminals are individually tight fit so as to be insulated. Following the assembly of the coils and terminals, the first compartment is filled with liquid polymer resin, which eventually solidifies to fully cover and insulate the assembled parts.
However above explained ignitors are difficult and costly to manufacture. Moreover, their assembly is a quite tedious procedure, which raises the production duration considerably.
The prior art document US 6,429,606 offers an improved design to overcome above-mentioned problems. In this document, an electronic gas-lighting device having a casing defined by a cup-shaped body made of electrically insulating material is disclosed. An electronic high-voltage-pulse generator is housed in an inner cavity of the casing accessible through a mouth of the cup-shaped body. An output terminal is connected to the electronic pulse generator and housed through a respective seating duct formed integrally with a bottom wall of the cup-shaped body. A connecting board carrying an electric circuit and extending the full length of the cup-shaped body is positioned substantially closing the mouth, inside the cavity, and carries, on a first face facing the cavity, the electronic pulse generator connected mechanically and electrically to one another and to the board by the board itself and the circuit, so as to be housed in one continuous compartment defined by the inner cavity of the casing and by the connecting board, and so as to be embedded, together with the connecting board, in a matrix of insulating polymer resin which fills the whole of the cavity up to a point flush with the mouth of the cavity. The board has at least one through opening enabling the polymer resin to be poured into the casing with the board already in position.
Another prior art document US 6,506,047 discloses an ignitor, which is grounded by means of a conducting U-shaped contact bracket that is gripped between the casing and the board of the range. The U-shaped contact bracket is connected to the board by soldering. The ignitor is removably fit to the board of the range via screws or two integrally formed teeth projecting laterally out from the walls of the casing. One of these teeth is on a lateral wall while the other is on a longitudinal one. However, this invention also suffers from the above-described drawbacks.
Another ignitor is further disclosed by the document WO/0006952 .
Even though these three inventions seem to resolve some difficulties associated with the prior art, they bring about further difficulties such as the necessity to align and tight fit all output and supply terminals into the ducts, simultaneously. To illustrate, for an ordinary cooking range with four burners, four output terminals are required. This means that, in total six (four output and two supply) terminals must be aligned and fit together during the assembly of the ignitor, which is a difficult task. Moreover, for tight fitting, a considerably high force is applied, which may result in deformation of either the terminals or other components. Said high force may also cause a rapture in the conducting wires and a final electrical discontinuity in the device.
It should also be recalled that, placing a connecting board and assembling all the components to the board both mechanically and electrically requires additional assembly steps as well as alignment problems. Therefore, both the connecting board and said additional steps increase the cost of the ignitor.
In addition to said disadvantages, more resin is used in said casings, since the whole volume of the casing is filled, rather than the partial volume in the two-compartment casings. This is an additional factor to increase the cost. Besides, if the terminals are misaligned with the ducts, the initially liquid resin leaks out of the casing through the ducts. Increasing number of output terminals increases the probability of leakage.

Disclosure of Invention

It is an object of the present invention to provide an electronic ignitor, which overcomes the disadvantages of the prior art and especially which allows for cheap and easy manufacturing and fast assembly.
According to the present invention, the two-compartment structure of the previous casings is preserved. However, it differs from the previous art in that it does not comprise any ducts on the casing. Two embodiments of the casing is provided, one with two side-by-side compartments closed by a common cap, and another with two compartments one-above the other, such that each closed by a different cap. Two assembly components with clips on their ends, project laterally outside from a wall of the casing for removable fitting of the ignitor to the cooking range. These components enable one-step mounting of the electronic ignitor to the conducting surface of the cooking range.
The secondary coil is wound around an insulating bobbin carcass that is produced with two integral ducts to house the output terminals. Moreover, output terminals are not tight fit to the ducts of the bobbin carcasses but rather, they are fit when the bobbin carcass is newly produced, i.e. when it is still hot, therefore soft. As the terminals are not tight fit to the casing, the alignment and deformation problems of the prior art techniques are overcome.
Free-of-ducts design of the casing allows for practical and flawless manufacture and assembly of the ignitor. Hence, the tedious assembly process of the previous technique is replaced with a simple one, which is unlikely to cause any malproductions.
At least one insulating cap covers the open surface of the casing. Said cap is permanently fastened to the casing by ultrasonic welding, in order to avoid unauthorized intervention. It also involves openings in the same number as that of output terminals, so that the ducts of the carcass housing the output terminals extend out of the cap when it is fastened onto the casing. Owing to said openings, output terminals may easily be connected to the electrodes on the cooking range.
At one end of the cap, there exists a protrusion extending towards a compartment of the casing and comprising three indentations formed side by side inside said protrusion. Said protrusion may or may not be integrally formed with the cap. Each of these indentations involves holes for the placement of respective supply and ground terminals. When the cap is positioned on the casing, supply and ground terminals remain inside the said indentations in said protrusion.
The ignitor of the present invention involves two different embodiments of grounding means, which allow for male-female type easy connection. The grounding means is made of a resiliently deformable, electrically conductive metal. Both embodiments enable one-step, simple grounding of the ignitor by simply attaching the grounding terminal to the grounding means. One end of the grounding means is bent for simple attachment to the grounding terminal and the other end extends outside the casing for providing electrical connection with the cooking range. Thus, the ignitor of the present invention brings another advantage over the prior art, as its grounding process does not require any specific joining such as soldering, welding, etc.

Brief Description of the Drawings

An exemplary embodiment of the present invention is explained in detail below by reference to the annexed drawings, in which:
Figure 1 shows a front view of the casing;
Figure 2 shows a top view of the casing;
Figure 3 shows a front view of the bobbin carcass;
Figure 4 shows a top view of the bobbin carcass;
Figure 5 shows a side view of the bobbin carcass;
Figure 6 shows a front view of the bobbin carcass without output terminal;
Figure 7 shows a top view of the primary coil;
Figure 8 shows a top view of the plate;
Figure 9 shows a front view of the plate;
Figure 10 shows a front view of the output terminal;
Figure 11 shows a side view of the cap;
Figure 12 shows a top view of the cap;
Figure 13 shows A-A section of the cap;
Figures 14 , 15, and 16 show front, top and side views of one embodiment of the grounding means, respectively;
Figures 17 and 18 show front and top views of another embodiment of the grounding means, respectively;
Figure 19 shows one embodiment of the grounding means assembled to the casing.
Figure 20 shows another embodiment of the grounding means assembled to the casing.
Figure 21 shows a schematic view of the circuit map of the ignitor;
Figure 22 shows an exploded side view of the ignitor;
Figures 23 , 24, 25, and 26 show left, top, front and right views of another embodiment of the ignitor;
Figures 27 and 28 show another embodiment of the ignitor when the top and bottom caps are open;
Figure 29 shows a section view of another embodiment of the ignitor;
Figures 30 and 31 show top and bottom caps of another embodiment of the ignitor;
Figures 32 and 33 show top and section views of the protrusion of another embodiment of the ignitor;
Figure 34 shows a front view of the plate of another embodiment of the ignitor;
Figures 35 and 36 show front and top views of the casing of an alternative embodiment of the casing;
Figures 37 and 38 show top and front views of the cap of an alternative embodiment of the casing;
Figure 39 shows front view of the assembly of an alternative embodiment of the casing.
Various parts in the drawings have been enumerated as follows:

1. Casing
2. Cap
3. Carcass
4. Output terminal
5. Primary coil
6. Plate
7. Board
8. Grounding means
9. Another embodiment of grounding means
10. Ground terminal
11. Positive supply terminal
12. Negative supply terminal

Best Mode for Carrying Out the Invention

The casing (1) of the electric ignitor is made of an insulating material and is in the form of a rectangular prism. It consists of two lateral (B and D), one front (A), one back (C) and a bottom side (E) and a top side (F). The casing (1) is divided into two compartments one for the coils and the other for the plate, separated from each other by an insulating wall, but still enabling the passage of connectors from the primary coil to the plate.
Figures 1 and 2 illustrate one embodiment of the casing (1) wherein the interior of the casing (1) is divided into two side-by-side compartments (1a and 1b) by a wall (1c) perpendicular to the interior of its bottom side (E). The top side (F) of the casing is open and both compartments (1a and 1b) are closed by a common cap (2). Two assembly means (1e) which are formed integrally with the casing, project perpendicularly outside from the front side (A). The assembly means (1e) are cylindrical or prismatic in shape. There exist one or two oppositely placed clips (1f) at the edge of each assembly means (1e). Said clips (1f) are also integral parts of the assembly means (1e). Said assembly means (1e) are designed for simple locking of the electronic ignitor to the board of cooking range (7). In an alternative embodiment (Fig. 20), the assembly means (1e) project from the edges at the intersections of the bottom (E) and the two side faces (B and D). Each of these assembly means involves two perpendicular planes with a screw hole on each.
Bobbin carcass (3) (Figs. 3-6), which is made of insulation material, preferably plastics, consists of a hollow (3c) cylindrical part (3b) around which the conductor wire of the secondary coil is wound and two integral (monobloc) ducts (3a) diagonally placed onto the two sides (G and H) of the cylindrical part. Two sides of the carcass (G and H) are parallel to each other. As soon as the bobbin carcass (3) is produced, when it is still warm or hot, one output terminal (4) is fit into a duct (3a). Thanks to the material characteristics of plastics, hot carcass shrinks as it cools down and permanently attaches to the output terminal, thereby eliminating the need to apply force for tight fitting of the terminal. This novel fitting method of the output terminals into the ducts of the carcass instead of ducts of the casing as in the prior art also prevents leakage of the polymer resin out of the casing. The two free ends of the secondary coil are electrically connected to the respective output terminals (4) after this attachment process.
As shown in Figure 7, a conductor wire (5a) is wound around a solid, cylindrical ferrite core (5b) to form the primary coil (5). Primary coil (5) is placed into the cylindrical hole (3c) of the bobbin carcass (3). Therefore, secondary coil is coaxial with the primary coil (5). The mounted coils (3 and 5) are put into one compartment (1b) of the casing (1). Then, polymer resin is poured into said compartment (1b) to ensure insulation and fixation of the coils in the casing (1).
Several electronic components such as grounding terminal (10) and supply terminals (11, 12) are attached to the plate (6) (Figs. 8 and 9).
Figures 11 and 12 show the insulating cap (2) having the dimensions to fully cover the open side (F) of the casing (1). There exist openings (2d, 2e, 2f, and 2g) on the cap (2) so that they correspond, in number, shape and dimension, to the ducts (3a) of the carcass (3) when the cap (2) is fixed permanently onto the casing (1) via ultrasonic welding. The total height of the carcass (3) is greater than the total depth of the cap (2) and the casing (1) so that the ducts, and therefore the output terminals (4) extend at least slightly out of the cap through the respective openings (2d, 2e, 2f, and 2g).
At one end of the cap (2), there is a protrusion (2i) extending in a direction perpendicular to the plane of the cap (Fig. 13). Said protrusion may or may not be produced integrally with the cap. There are three side-by-side indentations (2a, 2b, and 2c) inside said protrusion (2i) each with a hole (2h) at their bases. When the cap (2) is placed on the casing (1), supply (11 and 12) and ground (10) terminals on the plate (6) remain inside respective indentations (2a, 2b and 2c) passing through said holes (2h).
Figures 14 through 18 illustrate two embodiments of the grounding means (8 and 9). Grounding means (8) is manufactured by first cutting it from a resiliently deformable and electrically conductive sheet material, and then bending it into the desired shape. Said means (8) is placed outside the cap so as to form a male-female type connection with the ground terminal. One end of the means provides contact with the terminal residing in its indentation whereas the other end provides contact with the board of the appliance.
The first embodiment of the grounding means (8) is used together with the assembly means (1e) illustrated in Figures 14-16. This embodiment (8) involves a flat part (8d) to be placed on the cap. Another part (8a) extends into an indentation (2a, 2b or 2c) of the cap, perpendicular to said flat part (8d). This part (8a) comprises two curved portions for providing contact with the ground terminal in the indentation (2a). Grounding means (8) involves a third part (8b) for providing electrical contact with the board (7) of the cooking range. In one embodiment said part has a U-shape, which extends parallel to front side (A) of the casing (1) to be trapped between the casing and the board (7) of the cooking range. In another embodiment illustrated in Figure 16, said part (8b) is in the shape of a regular stripe which makes an angle with the front side (A) of the casing (1), again to be trapped between the casing and the board (7).
Second embodiment of grounding means (9) is used together with assembly means shown in Figure 20. Similar to the first embodiment, there exist a flat part (9d) to be placed on the cap and another part (9a) extending into an indentation (2a, 2b or 2c) of the cap, perpendicular to said flat part. This part (9a) comprises two curved portions for providing contact with the ground terminal in the indentation (2a, 2b or 2c). The third part (9b) extends in a direction parallel to one of the lateral sides (B or D), and has the same form as the assembly means. When one end (9a) of the grounding means (9) is attached to the grounding terminal which is housed in indentation (2a) of the cap (2), third part (9b) of the grounding means (9) resides on the assembly means (1e). Two holes (9c) on said part (9b) coincide with the holes of the assembly means. As soon as the casing is assembled to the board of the gas range via screws inserted through the holes on the grounding means and the holes of the assembly means, grounding is established.
In another embodiment of the invention (Figs. 23-34), the casing is still divided into two compartments via an insulating interior wall, however said compartments are placed one above the other. One compartment houses the plate whereas the other houses the primary and secondary coils. The interior wall involves means for the passage of conducting wires of the primary coil from one compartment to the other. The two compartments are open to two opposing sides of the casing and are closed by separate caps. Therefore, the cap of one compartment involves openings for the passage of the ducts of the bobbin carcass. On the other hand, the cap of the other compartment may have two different embodiments: In one embodiment (not shown in the drawings) said cap involves a protrusion for the supply and ground terminals. Again, the protrusion may or may not be an integral part of the respective cap. In another embodiment, said cap (Figures 26 and 31) is completely flat, in other words free of any protrusions, openings, indentations etc. In this latter embodiment, the protrusion (2i) (Figs. 32 and 33) is an independent piece, extending outside through an opening (2j) on a sidewall of the casing (Figures 23, 27 and 29). In this case, the supply and ground terminals (10, 11, and 12) are preferably bent perpendicular to the plane of the plate (6) into the indentations (2a, 2b and 2c) of the protrusion (2i).
Still another embodiment of the invention (Figs. 35-39) involves a casing divided into two side-by-side compartments via an insulating wall. However, in the present embodiment, in addition to the top side (F), a lateral side (D) of the casing is open as well (Fig. 35 and 36). Said lateral side is adjacent to the compartment (1a) housing the plate (6). As a result, the cap (2) comprises a section (2k) extending in a direction to close both open sides (D and F) of the casing (Fig. 37 and 38). Said cap (2) comprises a number of openings (2d, 2e, 2f and 2g) for output terminals, a protrusion (2i) for housing supply and ground terminals, and, if necessary, another opening (13a) for the push-button (13). Said openings and protrusions may be distributed on the cap depending on the specific requirements of the application.

Industrial Applicability

An exemplary assembly procedure of the present invention will be explained hereafter, by reference to the first embodiment of the ignitor (Fig. 22). As soon as the bobbin carcass is extracted from the mold and when it is still hot, therefore soft, the output terminals are easily attached to the ducts (3a). While cooling, the carcass shrinks and permanently adheres to the output terminals. Next, the conductor wire is simply tied to the output terminal and then wound on the cylindrical part of the carcass. Then, the primary coil (5) is placed in the secondary coil (3) in the direction of arrow A. Then, they are placed together in the compartment (1b) of the casing in the direction of arrow B. Polymer resin is poured into this compartment and let to cool down. The conductor wire of the primary coil (5) is connected to the plate, which is then placed in the other compartment (1a) of the casing, in the direction of arrow C. Next, the cap is placed on the casing (in the direction of arrow D) so that the output terminals extend into the openings (2d, 2e, 2f, 2g) and ground and supply terminals extend into the indentations (2a, 2b, 2c). Said cap is permanently connected to the casing by ultrasonic welding. Finally the grounding means is attached to the ground terminal, which rests in an indentation (2a), and placed on the cap in the direction of arrow E.

Claims

An electronic ignitor for gas burners, comprising a casing (1) of insulating material and in the form of a rectangular prism divided into two compartments (1a and 1b) separated from each other by an insulating wall (1c) having means for electrical connection from one compartment to the other, and having at least one open side (D and/or F), one or more secondary coils wound around one or more bobbin carcasses (3) placed in the first compartment (1b), a primary coil (5) nested in said secondary coil(s), a plate (6) placed in the second compartment (1a) for carrying several electronic components such as ground and supply terminals (10, 11, and 12), at least one assembly means (1e) for removably fitting said casing to the board (7) of a gas burner and characterized in that said bobbin carcass (3) includes integrally formed ducts (3a) to house output terminals (4) connected to the secondary coil, so that said output terminals (4) can be fit into the ducts as soon as they are produced when they are warm or hot, therefore soft, and in that the open side(s) of the casing (1) is permanently closed by at least one cap (2) which has means for easy access to the ground, supply and/or output terminals.
The electronic ignitor of Claim 1, characterized in that the compartments (1a and 1b) of the casing are placed side-by-side to be opened to the same side of the casing and be closed by a common cap (2).
The electronic ignitor of Claim 2, characterized in that the second compartment of the casing has an additional open side (D) and that said side is also closed by said cap via a section (2k) bent towards said open side.
The electronic ignitor of Claim 1, characterized in that the compartments (1a and 1b) of the casing are placed one above the other, being opened to different sides of the casing and closed by separate caps.
The electronic ignitor of any of the claims above, characterized in that the cap involves openings (2d, 2e, 2f, and 2g) that correspond, in number, shape and dimension, to the ducts (3a) of the carcass (3) when the cap (2) is fixed permanently onto the casing (1)
The electronic ignitor of any of the claims above, characterized in that the cap involves one or more holes (2h) to house the supply and ground terminals on the plate (6).
The electronic ignitor of Claim 6, characterized in that said holes (2h) are placed in one or more protrusions (2i) with one or more indentations (2a, 2b and 2c).
The electronic ignitor of Claim 7, characterized in that said protrusion (2i) is an integral part of the cap.
The electronic ignitor of Claim 7, characterized in that said protrusion (2i) is separately produced and than attached to the cap.
The electronic ignitor of any of claims 1 to 5 above, characterized in that the casing (1) involves one or more holes (2j) to house the supply and ground terminals on the plate (6).
The electronic ignitor of Claim 10, characterized in that said hole(s) (2j) house(s) one or more separately produced protrusions (2i) with one or more indentations (2a, 2b and 2c) to house said terminals (10, 11 and 12).
The electronic ignitor of any of the claims above, characterized in that said cap is permanently fixed to the casing via ultrasonic welding.
The electronic ignitor of any of the claims above, characterized in that it further comprises a grounding means (8 or 9) made of an electrically connecting, resiliently deformable material, involving mainly two parts, one (8a or 9a) for simple attachment to the ground terminal from outside the cap, and another (8b or 9b) for providing electrical connection between the ground terminal and the board of the gas burner.
The electronic ignitor of Claim 13, characterized in that said part of the grounding means (8 or 9) for attachment to the ground terminal involves one or more curved portions (8a or 9a), extending into the indentation (2a) housing the ground terminal, for providing electrical contact with the ground terminal.
The electronic ignitor of Claim 13 or 14, characterized in that said part (8b) of the grounding means (8) for providing contact with the board (7) has a U-shape, extending parallel to a side (A) of the casing (1) so as to be trapped between the casing and the board (7) of the gas range.
The electronic ignitor of Claim 13 or 14, characterized in that said part (8b) of the grounding means (8) for providing contact with the board (7) is in the shape of a stripe, which makes an angle with a side (A) of the casing (1) so as to be trapped between the casing and the board (7).
The electronic ignitor of Claim 13 or 14, characterized in that said part (9b) of the grounding means (9) for providing contact with the board (7) is extends in a direction parallel to one of the lateral sides (B or D), and has the same form as the assembly means so that said parts (9b) reside on the assembly means (1e) and the two holes (9c) on said part (9b) coincide with the holes of the assembly means.