EP3175176B1

EP3175176B1 - Flame ignition control device for burners or the like

Info

Publication number: EP3175176B1
Application number: EP15756694.4A
Authority: EP
Inventors: Raoul Bianchi; Gilberto BELDÌ; Marco CULATTI; Francesco DE CASTRO
Original assignee: Castfutura SpA
Current assignee: Castfutura SpA
Priority date: 2014-07-29
Filing date: 2015-07-22
Publication date: 2019-10-02
Anticipated expiration: 2035-07-22
Also published as: PL3175176T3; EP3175176A1; ES2762711T3; WO2016016773A1

Description

The present invention relates to a flame ignition control device comprising flame adjustment means connected to a gas supply source through at least one valve.
The adjustment means comprise a driving member composed of a driving shaft mounted so as to rotate about its own longitudinal axis mounted so as to translate in the direction of its own longitudinal axis, such to move between two extreme positions such to move from a maximum withdrawn condition to a maximum insertion condition respectively.
There is further provided a control unit intended to generate a spark, which control unit comprises two conductor elements connected to an electric supply source and a switch, which switch has a closed condition, where the two conductor elements are connected with each other, and an open condition, where the two conductor elements are not connected with each other.
The switch further passes from the open condition to the closed condition by the movement of a member switching the condition of the switch which is moved by the translation of the driving shaft, such that the closed condition of the switch corresponds to the maximum insertion condition of the driving shaft.
The one just described is the common arrangement of a control device for igniting a flame through a gas cock.
As it will be clear from the description below, the present invention preferably is directed to gas cocks, but it can be easily adapted to different systems.
For example it is possible to use the device of the present invention applied also to controls equivalent to the gas cock, such as for example electric thermostats, gas thermostats, both for detecting signals and for carrying out controls.
With a particular reference to gas cocks, such devices are known and widely used in combination with burners employed in several fields, both civil and industrial ones, and generally they have a control knob acting on a driving shaft, serving for opening/closing the valve connecting it to the gas supply source.
It is specified that for operating a gas cock the current international regulations about safety matters provide it to be rotated anticlockwise by making a release force, allowing it to translate along the longitudinal axis of the driving shaft. Such force for the safety cocks have to be kept for few seconds in order to excite the magnet supervising the burner operation.
An arrangement of a typical burner for example is described in the patent application WO2013/076632 , to the applicant.
Therefore having one hand busy in this manner, it would be impossible, with the other hand, to press the button that, by turning the igniter on, namely generating a spark, allows the burner to be turned on.
Some devices known in the prior art overcome such problem by providing control systems that, by using only one hand, allow both the functions to be carried out, controlling the gas cock and controlling the igniter.
This solution is accomplished by assembling a momentary or permanent switch on the cock then by controlling it by the driving shaft of the cock by means of linkages and/or transmissions.
Examples such devices are provided by documents WO2011/082882 and WO2008/135839 .
According to the most widespread type of devices known in the prior art, the driving shaft has two degrees of freedom, firstly it is necessary to carry out a translation along its own longitudinal axis, then to rotate it to adjust the amount of gas to be supplied to the burner, that is to adjust the generated flame.
The translation of the driving shaft along its own longitudinal axis allows the valve to be opened and also a spark to be generated, by the provision of a switch that, once operated namely in the closed condition, causes the two conductor wires to be connected.
Generally the control unit is rigidly assembled to the device body, it houses two series of wires therein mechanically crimped to two contacts that are operated by a control lever.
The control lever is then controlled by a control washer rigidly fitted on the shaft of the gas cock. The pressure exerted on the cock activates the contact of the switch by means of the control lever.
The suggested solution, even if allowing a gas cock of a burner to be operated only with one hand, however has some drawbacks.
Firstly such solution provides the switch to be off-centered with respect to the axis of the driving shaft with the consequent need of having an inclined lever that causes inaccuracy in transmitting the control and therefore in operating the switch.
Moreover the brittleness of the control lever of the devices known in the prior art leads to failures both during the application and during the assembly of the products.
The arrangement of the devices known in the prior art just described, requires the control unit to have the body open on one of the sides, without a particular protection against water. In case of liquid overflowing or leaking, very frequent by the way, through the hole placed underneath the control knob of the cock, the same liquids go in contact with the switch with a consequent loss in the functionality. This obliges the end user to put suitable rubber gaskets for protecting the control switch under the knob.
Therefore there is a need not satisfied by the devices known in the prior art for providing a flame ignition control device that overcomes the drawbacks described above, while guaranteeing an efficacious operation, low production costs and a high adaptability to the different burners on the market.
Further, a flame ignition control device such as described above, wherein the switching member is provided coaxial to the driving shaft, is known from document WO2011/084729 .
The coaxial positioning of the switching member not only allows a gas burner to be turned on only using one hand and with only one control, but it also gives to the device of the present invention accuracy in carrying out the control and stiffness.
The above aims are achieved by a flame ignition control device according to the appended claim 1. Further detailed characteristics and advantages are described in the dependent claims.
According to the invention, the switching member is composed of a support body placed underneath the driving shaft.
Such support body is interposed between the driving shaft and the valve body, and it houses the control unit and at least one driving pin therein.
The driving pin passes from a condition retracted into the support body, where the driving pin abuts against the walls of the valve body, to a condition withdrawn with respect to the support body.
The retracted condition of the driving pin corresponds to the maximum insertion condition of the driving shaft.
There are further provided means for fastening the support body to the driving shaft, such that the support body is integral with the driving shaft.
As it will be clearly set forth below the support body is integral with the driving shaft only for the translation along its own longitudinal axis.
Moreover as it will be clearly shown in some shown embodiments, such arrangement combines also the protection against possible liquid leakages with the properties described above about stiffness of the device and accuracy of the control.
As it will be described below, the control unit houses the conductor elements and the electric part is protected by the support body that does not allow liquids to go in contact with the switch, protecting its operation.
It results in a reduction in maintenance costs, as well as a reduction in production costs since it is not necessary to provide further components such as for example gaskets or the like, in order to avoid liquid from entering into the control unit.
According to an improvement of the device of the present invention, the driving pin is firmly kept in the withdrawn condition by at least one elastic element, such that the passage from the withdrawn condition to the retracted condition of the driving pin moves a driving lever, which driving lever acts on the switch for switching it from the open condition to the closed condition.
The arrangement of the driving lever and of the driving pin can be any one known in the prior art.
As it will be shown in the description of the shown embodiments, the control lever is a cam whose movement moves a part of the switch such to guarantee the closed condition thereof.
According to a variant embodiment there are provided means for locking the support body, which locking means fasten the support body to the valve body, such to allow it to translate integrally with the driving shaft along the longitudinal axis of the driving shaft, preventing the support body from rotating.
Such aspect is important since the locking means work in synergy with the fastening means: the fastening means firmly fasten the support body to the driving shaft such to make it integral therewith, while the locking means lock the support body to the valve body such to prevent it from rotating.
It results that the support body is free to translate integrally with the driving shaft and freely with respect to the valve body, however without the need of rotating like the driving shaft.
Therefore the degrees of freedom of the driving shaft in this case are not compromised.
Advantageously the support body comprises an outer case with a substantially parallelepiped shape, open at at least the lower side.
The outer case provides an area housing the control unit and it has at least one upper wall, from which at least one fastening tooth extends for fastening the outer case to the driving shaft.
The opening at the lower side allows the device of the present invention to be easily inspected, while maintaining the upper area as protected, which is the most critical area due to the passage of liquids inside the control unit.
Preferably the outer case will be made of a plastic material, such to easily adapt the device of the present invention to the different valve bodies or to assembling needs.
According to a further improvement the driving shaft has, at its own lower end, an annular narrowing, the at least one fastening tooth being fastened at the annular narrowing.
The fastening of the support body obtained in this manner is able to withstand several dozens of kilograms of thrust, however allowing the driving shaft to freely rotate.
According to a possible embodiment, the outer case has a lower part providing a shape complementary to the upper part of the valve body, with which it is in contact.
Thus the rotation of the outer case with respect to the valve body is avoided during the operation of the driving shaft.
According to a further variant embodiment, the outer case has at least one, preferably two, side walls, said locking means being composed of at least one tab extending downwardly from each of the two side walls.
The provision of the tabs extending from the support body along the valve body prevents the support body from rotating, thus making it integral with the valve body.
Such tabs can be further made as one piece with the support body.
A variant embodiment of the device of the present invention provides the upper part to be inclined towards the valve body.
Preferably the upper wall has an upwardly facing concavity such to form a surface inclined downwardly or a cambered surface, such to discharge possible liquids coming from the top towards regions far from the control unit and the switch.
According to one embodiment the upper wall has an annular element extending towards the driving shaft, which annular element is placed coaxial to the driving shaft.
The provision of such annular element gives to the device of the present invention a further protection against water since the annular element can be provided with such a height to exit with respect to the surface of the top where the burner is installed in combination with the device of the present invention.
The switch provided inside the control unit can be composed of any switch known in the prior art.
Preferably the switch is composed of two sheet-like elements, of which a fixed element and a movable element, made of elastically deformable conductive material.
The movable element is moved by the switching member such that the fixed element is in contact with the movable element in the closed condition of the switch, while the fixed element is separated with respect to the movable element in the open condition of the switch.
There are further provided hooking members for fastening the movable element and/or the fixed element to at least one of the two conductor elements.
The arrangement of the switch just described, in combination with the characteristics set forth above related to the device of the present invention, allows complex systems of flame ignition control devices for burners or the like to be made.
In particular the switches of each device can be connected with each other by means of the conductor elements composed of connection wires, such to form a harness intended to satisfy the quantitative needs of a single appliance and/or product.
Therefore the characteristics just described advantageously allow complex switch systems to be made without interruption, in particularly a switch for each gas cock, called as harness, also as combination of a momentary and continuous switch such to make a control system under the knob and to allow complex cooking systems with several cocks to be easily assembled.
Preferably the hooking members are composed of housing seats obtained in the thickness of the walls of the movable element and of the fixed element.
The housing seats have a leading entrance and a housing area having a profile complementary to at least a part of the section of the conductor elements.
Thus a quick press connection is accomplished and without welding the switch to the conductor elements.
According to a possible embodiment there is provided at least one sensor intended to detect the position of said driving shaft.
As an alternative or in combination it is possible to provide at least one sensor intended to detect the operation of the control unit.
These and other characteristics and advantages of the present invention will be more clear from the following description of some embodiments shown in the annexed drawings, wherein:

Fig.1a is a flame ignition control device of the prior art;
Fig.1b is the control unit of the device of figure 1a;
Fig.2 is a preferred embodiment of the device of the present invention;
Figs.3 and 4 are two perspective views of the support body of the device of the present invention;
Fig.5 is a variant embodiment of the control unit of the device of the present invention;
Fig.6 is a variant embodiment of the device of the present invention.

It is specified that the figures attached to the present patent application are about some variant embodiments of the device of the present invention and are shown here in order to better explain the advantages and the characteristics of the device of the present invention.
Such variant embodiments therefore have to be intended as explanatory and not as a limitation of the inventive concept of the present invention.
Particularly figures 1a and 1b show a flame ignition control device belonging to the prior art.
Such device comprises flame adjustment means connected to a gas supply source through at least one valve.
The adjustment means comprise a driving member composed of a driving shaft 1 mounted so as to rotate about its own longitudinal axis mounted so as to translate in the direction of its own longitudinal axis, such to move between two extreme positions such to move from a maximum withdrawn condition to a maximum insertion condition respectively.
Therefore the driving shaft 1 can rotate in the direction denoted by arrow A for adjusting the amount of gas to be supplied to a burner and it can translate in the direction of arrow B.
The translation allows the gas supply valve 2 to be opened, as well as the control unit 3 to be operated as it will be described below.
The device comprises a control unit 3 intended to generate a spark, which comprises two conductor elements 31, 32 connected to an electric supply source and a switch 4, which has a closed condition, where the two conductor elements 31, 32 are connected with each other, and an open condition, where the two conductor elements 31, 32 are not connected with each other.
The switch 4 passes from the open condition to the closed condition by the movement of a member switching the condition of the switch 4, which is moved by the translation of the driving shaft 1, such that the closed condition of the switch 4 corresponds to the maximum insertion condition of the driving shaft 1.
Particularly in the device known in the prior art shown in figure 1a, the driving member is composed of a control level 11 and of a washer 12.
The washer 12 is rigidly fitted on the driving shaft 1 and it pushes the control lever 11 downwardly when the driving shaft 1 translates downwards.
The pressure exerted on the driving shaft 1 therefore moves the control lever 11 having its end part inserted into the control unit 3.
The switch 4 is composed of a movable contact 42 and a fixed contact 41, while the control unit 3 is rigidly assembled to the body of the device, it houses two series of wires 31, 32 therein mechanically crimped to the movable 42 and fixed 41 contacts.
The control lever 11 pushed downwardly in turn pushes the movable contact 42 such to elastically deform it and to put it in contact with the fixed element 41, such to achieve the closed condition of the switch 4.
The closed condition of the switch 4 allows the spark to be generated that in combination with the gas allows the flame to be ignited.
Therefore it is clear how the maximum insertion condition of the driving shaft 1 corresponds to the closed condition of the switch 4 and how the switching member, composed of the lever 11 and of the washer 12, is not coaxial to the driving shaft 1.
Unlike the device shown in figures 1a and 1b, the switching member of the device of the present invention is provided coaxial to the driving shaft 1.
Particularly figures 2 and 3 show a preferred embodiment of the device of the present invention.
According to such embodiment, the switching member is composed of a support body 5 placed underneath the driving shaft 1, and interposed between the driving shaft 1 and the body of the valve 2.
The support body 5 houses the control unit 3 and at least one driving pin 51 inside it, which driving pin 51 moves from a condition retracted into the support body 5, where the driving pin 51 abuts against the walls of the valve body 2, to a condition withdrawn from the support body 5.
The retracted condition of the driving pin 51 corresponds to the condition of maximum insertion of the driving shaft 1.
There are further provided means 52 for fastening the support body 5 to the driving shaft 1, such that the support body 5 is integral with the driving shaft 1.
The translation of the shaft 1 along the arrow B of figure 2, causes the pin 51 to be withdrawn from or inserted into the support body 5.
Since the support body 5 is integral with the driving shaft 1, a pressure of the driving shaft 1 downwards causes the support body 5 to translate downwards causing the driving pin 51 to abut against the upper wall 21 of the valve body 2.
The driving pin 51 by going into the support body 5 closes the switch 4 inserted into the control unit 3 housed into the support body 5.
Figure 5 shows a possible variant embodiment of the device of the present invention, intended to show the operating principle of the pin 51 and of the switch 4.
With a particular reference to figure 4, the driving pin 51 is firmly kept in the withdrawn condition by at least one elastic element 52, such that the movement from the withdrawn condition to the retracted condition of the driving pin 51 moves a driving lever 53.
The driving lever 53 acts on the switch 4 for switching it from the open condition to the closed condition.
Therefore the driving level 53 acts as a kind of cam on the movable contact 42 of the switch 4: by exerting a pressure on the driving shaft 1, the spring 52 is compressed, the pin 51, abutting on the upper wall 21 of the valve body 2, moves upwardly, drags the lever 53 that acts as a cam and it pushes the movable contact 42 towards the fixed contact 41, closing the switch 4.
Once the pressure on the driving shaft 1 ends, the spring 52 is released and it pushes downwardly the driving pin 51 that is no more hindered by the upper wall 21 of the valve body 2 and then the lever 53 stops pressing on the movable contact 42, causing the switch 4 to return to the open condition.
Such arrangement moreover allows different types of switches known in the prior art to be used, on the basis also of the manufacture of the driving lever 53.
The switch, depending on the cam that is made, can be of the momentary, press type, particularly useful for controlling igniters or of the rotary and continuous type, particularly useful for controlling electronic control systems.
It results that the support body 5 can house inside the control unit 3 both the types of operation, momentary and/or continuous one.
It is specified that the figures show only the momentary version of the switch, but it is possible to use also a continuous switch without requiring excessive changes to the device shown in the figures.
For example for making a continuous switch, it is possible to provide a cam suitably shaped in the void to solid ratio to close the contact for a given number of angle degrees.
As it is shown in figures 2 and 3, the support body 5 provides one access only from the lower side, to the upper part and side parts of the control system, except for the inlet and outlet of the conductor elements 31 and 32 there are no apertures or joints of any type such to avoid possible passages for the entrance of liquids.
The region of the control unit 3 is accessible and assembled only from the lower part of the support body 5.
Moreover the support body 5 can provide protection elements 54 placed near the inlet and outlet of the conductor elements 31 and 32, such protection elements 54 can divert possible liquids coming from above.
Therefore advantageously the support body 5 comprises an outer case with a substantially parallelepiped shape, which outer case is open at least at the lower side, the outer case providing a region for housing the control unit 3.
Moreover the outer case has at least one upper wall 55 at least one fastening tooth 56 extending therefrom for fastening the outer case to the driving shaft.
With a particular reference to figures 2 and 3, the outer case comprises three fastening teeth 56, such to homogeneously distribute the pressing thrust exerted on the driving shaft 1.
Moreover the region for housing the control unit 3 can be closed also at the lower side, such to prevent external agents from entering therein.
Advantageously the driving shaft 1 has, at its own lower end, an annular narrowing.
Such annular narrowing forms a sealing groove to which the three fastening teeth 56 are fastened, such as shown in figure 2.
According to a further embodiment, there are provided means for locking the support body 5, which fasten the support body 5 to the valve body 2, such to allow it to translate integrally with the driving shaft 1 along the longitudinal axis of the driving shaft 1, preventing the support body 5 from rotating.
Such locking means for example can be made by means of a form-fit of the support body 5 with the outer walls of the valve body 2.
As an alternative or in combination, it is possible to provide the outer case to have at least two side walls 57, the locking means being composed of at least one tab 58 extending downwardly from each one of the two side walls 57.
Preferably the support body is made of a plastic material and it is possible to provide the tabs 58 and the fastening teeth 56 to be made as one piece with the outer case.
Moreover according to a possible variant embodiment the upper wall 55 of the support body 5 is inclined towards the valve body 2.
According to a further embodiment, it is possible to adapt the shape of the support body 5 to the shape of the valve body 2 not during the production step but directly by the customer in the assembling step on the line. In this case the rear plastic of the support body 5 is a standard plastic where an adapter still made of plastic will be inserted for the coupling to the selected valve.
Figure 6 shows a further embodiment of the device of the present invention, particularly the upper wall 55 has an annular element 551 extending towards the driving shaft 1.
The annular element 551 preferably is placed coaxial to the driving shaft 1.
As set forth above the annular element 551 allows a higher protection against falling liquids to be obtained and in order to guarantee a complete protection it is further possible to place a suitable gasket, such as an O-ring, placed at the base of the annular element 551, at the upper wall 55.
Such as shown in detail in figure 5, the switch 4 advantageously is composed of two sheet-like elements, of which a fixed element 41 and a movable element 42, made of elastically deformable conductive material.
The movable element 42 is moved by the switching member such that the fixed element 41 is in contact with the movable element 42 in the closed condition of the switch 4, and the fixed element 41 being separated from the movable element 42 in the open condition of the switch 4.
There are further provided hooking members for fastening the movable element 42 and/or the fixed element 41 to at least one of the two conductor elements 31, 32.
With a particular reference to figure 5, the fixed element 41 and the movable element 42 are connected to both the conductor elements 31 and 32.
The hooking members are composed of housing seats 43 formed in the thickness of the walls of the movable element 42 and of the fixed element 41.
In particular the housing seats 43 have a leading entrance and a housing area having a profile complementary to at least a part of the section of the conductor elements 31 and 32.
Thus a quick connection of the contacts of the switch 4 to the conductors 31 and 32 is obtained by compressing the conductors 31 and 32 into two slits, suitably shaped and being part of the contacts of the switch, namely the elements 41 and 42.
According to a further embodiment there is provided at least one sensor intended to detect the position of the driving shaft 1.
The device of the present invention therefore can incorporate a position transducer, for example angle/resistance, a magnetic, position one made by suitable arrangements, for example by the deposition of a resistive paste on a substrate such to have a continuous transducer or for example by using fixed resistances such to have a stepped transducer.
Finally it is possible to provide the presence of a sensor intended to detect the operation of the control unit.
Such sensor can be any type known in the prior art and for example it can be intended to evaluate the condition of the switch 4, that is to evaluate whether it is open or closed, also on the basis of the condition of the driving shaft 1.
It is further possible to provide in combination with such sensor audible or visual warning devices, intended to warn a possible user about the malfunction of the control unit 3.

Claims

Flame ignition control device comprising flame adjustment means connectable to a gas supply source through at least one valve (2), which adjustment means comprise a driving member composed of a driving shaft (1) mounted so as to rotate about its own longitudinal axis and mounted so as to translate in the direction of its own longitudinal axis, such to move between two extreme positions such to move from a maximum withdrawn condition to a maximum insertion condition respectively,
there being provided a control unit (3) intended to generate a spark, which control unit (3) comprises two conductor elements (31, 32) cannectable to an electric supply source and a switch (4), which switch (4) has a closed condition, where the two conductor elements (31, 32) are connected with each other, and an open condition, where the two conductor elements (31, 32) are not connected with each other,
said switch (4) passing from the closed condition to the open condition by the movement of a member switching the condition of the switch (4), which switching member is moved by the translation of said driving shaft (1), such that the closed condition of said switch (4) corresponds to the maximum insertion condition of said driving shaft (1),
said switching member is provided coaxial to said driving shaft (1),
characterized in that
said switching member is composed of a support body (5) placed underneath said driving shaft (1), interposed between said driving shaft (1) and a body of said valve (2), which support body (5) houses said control unit (3) and at least one driving pin (51) inside it, which driving pin (51) moves from a condition retracted into the support body (5), where the driving pin (51) abuts against the walls of said valve body (2), to a condition withdrawn from said support body (5), the retracted condition of said driving pin (51) corresponding to the condition of maximum insertion of said driving shaft (1),
there being provided means for fastening said support body (5) to said driving shaft (1), such that said support body (5) is integral with said driving shaft (1) during the translation movement.
Device according to claim 1, wherein the driving pin (51) is firmly kept in the withdrawn condition through at least one elastic element (52), such that the passage from the withdrawn condition to the retracted condition of said driving pin (51) moves a driving lever (53), which driving lever (53) acts on said switch (4) for moving it from the open condition to the closed condition.
Device according to claim 1, wherein there are provided locking means (58) for said support body (5), which locking means (58) fasten said support body (5) to the body of said valve (2), such to allow said support body (5) to translate integrally with said driving shaft (1) in the direction of the longitudinal axis of said driving shaft (1), preventing said support body (5) from rotating.
Device according to claim 1, wherein said support body (5) comprises a outer case with a substantial parallelepiped shape, which outer case is opened at least at the lower side, said outer case providing an area housing said control unit (3), said outer case having at least one upper wall (55), at least one fastening tooth (56) extending from such upper wall (54) for fastening said outer case to said driving shaft (1).
Device according to claim 4, wherein the driving shaft (1) has, at its lower end, an annular narrowing, said at least one fastening tooth (56) being fastened at said annular narrowing.
Device according to claim 4, wherein said outer case provides a lower part having a shape complementary to said valve body (2), such to avoid the rotation of said outer case with respect to said valve body (2) during the operation of the driving shaft (1).
Device according to claim 4, wherein said upper wall (55) is inclined in the direction of said valve body (2) .
Device according to claim 4, wherein said upper wall (55) has an annular element (551) extending in the direction of the driving shaft (1), which annular element (551) is placed coaxial to the driving shaft (1).
Device according to claim 1, wherein said switch (4) is composed of two sheet-like elements, of which a fixed element (41) and a movable element (42), made of elastically deformable conductive material,
the movable element (42) being moved by said switching member such that the fixed element (41) is in contact with the movable element (42) with the switch (4) in the closed condition and the fixed element (41) being separated with respect to the movable element (42) with the switch (4) in the open condition,
there being provided hooking members for fastening the movable element (42) and/or the fixed element (41) to at least one of the two conductor elements (31, 32).
Device according to claim 9, wherein the hooking members are composed of housing seats (43) obtained in the thickness of the walls of the movable element (42) and of the fixed element (41),
which housing seats (43) have a leading entrance and a housing area having a profile complementary to at least a part of the section of said conductor elements (31, 32) .
Device according to claim 1, wherein there is provided at least one sensor intended to detect the position of said driving shaft (1).
Device according to claim 1, wherein there is provided at least one sensor intended to detect the operation of said control unit (3).