EP1536181B1 - Gas cock and gas cooking plate - Google Patents

Description

The invention relates to a gas tap for a gas burner and a gas hob, in which the gas cock is used, which has an actuating shaft which is rotatably and / or axially displaceably mounted in a housing of the gas cock, and with a control knob for exercising a rotary and / or pressure movement is connected to the actuating shaft, which is guided through a passage opening of a cover part of the housing from the gas valve.

Out DE 35 41 132 C2 is a gas tap for gas burners known. The gas tap has a valve body with a lid in which a bore for supporting an actuating shaft is formed, by means of which a gas flow rate through the gas valve is adjusted. Due to manufacturing tolerances between a outer periphery of the actuating shaft and an inner periphery of the cover bore a clearance exists, whereby the actuating shaft is slightly radially movable. Such a radial movement of the actuating shaft is particularly disadvantageous in the case of actuating shafts which protrude over a considerable length from the cover part of the gas cock.

From the GB-A 1258576 a gas regulator and an ignition system for a gas burner is known. These include a gas tap for controlling the gas supply of the burner and a means for generating spark, which is triggered at a predetermined position of the activated gas tap. The spark generator instantaneously generates a spark over the spark gap when triggered to ignite the gas flowing out of the burner. Gas regulator and ignition system further comprises a delay means, which initiates a delay when turning the gas tap, before the gas tap reaches the predetermined position. This delay is long enough to ensure an ignitable mixture at the spark gap.

The object of the present invention is to provide a gas tap or a gas hob, in which an ease of use in adjusting a gas flow rate through the gas tap is improved.

The object is achieved by a gas tap with the features of claim 1 or by a gas hob with the features of claim 10. The document GB-A 1258576 discloses the preamble of claim 1. Accordingly, the guide element is formed with a retaining flange for holding additional components. The retaining flange of the guide element is formed with at least one recess which allows access to a bypass nozzle of the gas tap. For a pre-setting of the gas tap, the bypass nozzle is to be replaced. Such replacement of the bypass nozzle can be done due to the free access, without disassembling the guide element of the gas tap.

Advantageously, the guide element may be formed as an axially elongated guide sleeve. As a result, a large-area sliding contact between the actuating shaft and the guide sleeve is ensured. In terms of manufacturing technology, it is advantageous if the guide element consists of plastic. Thus, the guide member can be inexpensively and easily manufactured as a plastic injection molded part.

A functionality of the guide element is increased if the retaining flange (69) is designed to hold additional components designed as a printed circuit board (99) and / or as a switch (51) and / or as an LED display (21). The additional components are therefore held directly on the gas tap. This results in a compact set of components consisting of several interacting components. The space requirement for the components in the gas hob is therefore reduced. Additional mounting parts for mounting the additional components can be saved.

Preferably, the guide element may be formed with at least one fastening element for attachment to the gas cock housing. It is advantageous if the fastener is supported on the gas tap housing via a releasable latching connection.

For an electronic detection of a rotational position of the actuating shaft, a control cam may be attached to the actuating shaft, which actuates a switch on rotation of the actuating shaft, which passes a corresponding signal to an electronic control device. Advantageously, the switch can be held directly on the retaining flange or on the printed circuit board, which in turn on the retaining flange is mounted. As a result, a compact design and a reliable interaction between the switching cam of the actuating shaft and the switch is achieved.

Preferably, the guide element can be used to support the switching cam. As a result, a simple and space-saving storage of the switching cam is achieved in a compact manner. Advantageously, the actuating shaft can be rotatably mounted on the outside on the guide element.

According to one embodiment, the guide element may additionally be formed with a stroke stop. This can be made much more robust in comparison to the stroke stops normally provided in the gas tap. Against the stroke stop of the guide element can beat the actuating shaft with its switching cam at a force exerted on the actuating shaft pressure movement.

Furthermore, the stroke stop of the guide element and the switching cam may be formed in the region of their stop surfaces with metal inserts. As a result, an impairment of the operability of the gas tap impairing abrasion between the switching cam and the stroke stop of the guide element is reduced. Compared to abutting plastic surfaces thus friction-related wear between the guide member and the control cam can be reduced.

Figur 1

in einer perspektivischen Darstellung das Gaskochfeld;

Figur 2

ein Blockdiagramm exemplarisch für einen Gasbrenner des Gaskochfeldes;

Figur 3a bis 3c

jeweils in einer perspektivischen Darstellung einen Gashahn ohne Führungselement, einen Gashahn mit aufgesetztem Führungselement sowie einen Gashahn mit Führungselement und darauf gelagertem Schaltnocken; und

Figur 4

in einer perspektivischen Teilansicht vier Gashähne des Gaskochfeldes mit zugeordneter Leiterplatine sowie zugeordnetem Schalter.

Hereinafter, an embodiment of the gas hob according to the invention will be described with reference to the accompanying figures. Show it:

FIG. 1

in a perspective view of the gas hob;

FIG. 2

a block diagram of an example of a gas burner of the gas hob;

FIGS. 3a to 3c

each in a perspective view of a gas cock without guide element, a gas cock with attached guide element and a gas cock with guide element and mounted thereon switching cam; and

FIG. 4

in a perspective partial view four gas taps of the gas hob with associated printed circuit board and associated switch.

That in the FIG. 1 shown gas hob has four schematically indicated gas burner 1, 3, 5, 7, which are guided by a cover plate 9 of the gas hob. On the front side, the gas hob has a control bar 11. In each of these a gas knob 13, 15, 17, 19 is arranged for each of the gas burners. Furthermore, each of the gas burners an operating indicator 21, 23, 25, 27 associated, each of which is designed as an LED. Not shown are the FIG. 1 the gas burner associated pot carrier for parking Gargutbehältnissen on the gas burners.

The operation of the gas hob is based on the block diagram of the FIG. 2 described. For clarity, the block diagram is the FIG. 2 limited to the gas burner 1 with the associated control knob 13 and the power indicator 21. The other gas burners 3, 5, 7 are connected in a corresponding manner in the gas hob. For flame monitoring is the gas burner 1 according to the FIG. 2 associated with an ionization electrode 29, with the presence of a flame of the burner 1 is detected. By means of the flame, a gap between the ionization electrode 29 and the gas burner 1 can be electrically bridged, whereby a corresponding signal is passed from the ionization electrode 29 via a signal line 31 to an electronic control device 33. The electrical control device 33 is connected via a further signal line 35 with a main valve 37 in connection. The main valve 37 is arranged in a main gas line 39, which is coupled to a gas supply network. On the output side, the main valve 37 is connected to a distributor pipe 41, from which partial gas lines 42 each lead to the gas burners 1, 3, 5, 7.

In the FIG. 2 only the gas path to the gas burner 1 is shown completely. In the leading to the gas burner 1 partial gas line 42, a gas cock 45 is arranged, with which a gas flow rate to the gas burner 1 is set. Whose actuation shaft 47 is connected via a shift linkage 49 with the rotary knob 13. A signal generator or switch 51 detects a rotational position of the actuating shaft 13 and outputs this via a gas supply line 53 to the electronic control device 33. In a corresponding manner, the rotational positions of the other control knob 15, 17, 19 via the with dashed line indicated signal lines to the electronic control device 33 passed. About the electronic control device 33, the operation indicator 21 of the gas burner 1 is controlled.

To start a burner operation is in accordance with the FIG. 2 the control knob 13 is first rotated from its zero position, in which the gas tap 45 is in a closed position. This initial rotation is detected by the signal generator 51, which passes a corresponding signal to the electronic control device 33. Subsequently, the electronic control device 33 opens the normally closed main valve 37, so that via the main gas line 39 and the partial gas line 42, a gas flow rate is supplied to the gas burner 1. At the same time, the electronic controller 33 controls the ionization electrode 29 to ignite the gas burner 1. An adjustment of the gas flow rate to the gas burner 1 by means of the actuating shaft 47 of the gas tap 45. Its flow cross section can be changed by turning the operating shaft 47 accordingly. During operation of the gas burner 1, the LED display 21 is permanently switched on.

In the FIG. 4 is shown in a perspective partial view of the output side connected to the main valve 37 manifold 41 with each coupled gas tapers 45. The gas taps 45 are on the input side with the manifold 41 fluidly connected. According to the present embodiment, in the FIG. 4 illustrated gas taps 45 designed for dual-circuit burners with an inner flame circle and an outer circle of flames. In this case, depending on the rotational position of the control knob at low power settings, only the inner flame of the gas burner is supplied with gas. For larger power settings, the gas tap also releases a gas supply to the outer flame circuit of the gas burner. The in the FIGS. 3a to 3c Gas faucets 45 shown therefore each have two gas supply lines 53, 55. These are in the FIGS. 3a to 3c as well as the FIG. 4 indicated by arrows and direct the gas flow to the inner and / or outer flame circuit of the associated gas burner.

In the FIGS. 3a to 3c a gas tap 45 is shown in various stages of assembly. According to the FIG. 3a the gas tap 45 has a housing part 57, which is usually formed from a brass casting. In the housing part 57, the actuating shaft 47th rotatably mounted and axially displaceable. Depending on its rotational position, the actuating shaft 47, with its gas cock chute provided inside the gas cock, defines a gas flow cross-section to the gas supply lines 53, 55. The gas tap 45 also has a cover part 59, which is usually formed from a steel sheet and is screwed by means of screws 61 to the housing part 57. In the cover part 59 of the gas tap 45, a passage opening 63 is formed. This is followed by a cover-side guide flange 65 connects. Due to manufacturing tolerances, the actuating shaft 47 is guided by the lid part 59 with play. In the FIG. 3b the gas tap 45 is shown with a sleeve-like guide member 67. The protruding from the lid part 59 actuating shaft 47 is guided by the hollow cylindrical guide member 67. It is almost free of play in sliding contact with the actuating shaft 47th

The sleeve-like guide element 67 is formed on a gas tap facing the end with a retaining flange 69 which has circumferential locking elements 71. These engage behind an edge projection 73 of the cover part 59, so that the retaining flange 69 is pressed firmly against an annular shoulder 75 of the cover part 59. The retaining flange 69 of the guide element 67 also has on the circumferential side two recesses or recessed portions 77, 79. As a result, an exchange of bypass nozzles 81, 83 of the gas tap is made possible without disengaging the guide element 67 from the gas tap.

In the Figure 3c is on a sleeve portion 85 of the guide member 67 a hollow cylindrical cam 87 rotatably mounted. The switching cam 87 is connected at its upper end face 89 fixed to the actuating shaft 47. This is by a in the FIG. 3a shown transverse bore 91 in the actuating shaft 47, an unillustrated metal pin out. Subsequently, the switching cam 87 is set to the guide member 67. The metal pin is arranged in this way in a form-fitting manner in a recess which is formed on the inside on the end face 89 of the switching cam 87. The switching cam 87 is therefore non-rotatably connected in the radial direction with the actuating shaft 47. An axial displacement of the switching cam 87 along the actuating shaft 47 is prevented by a plugged onto the actuating shaft 47 snap ring 93. The switching cam 87 is thus arranged with its end face 89 between the snap ring 93 and the metal pin, not shown.

When applying a pressure movement on the actuating shaft 47 of the metal pin, not shown beats against a in the FIG. 3b This limits the pressure movement of the actuating shaft 47. To reduce abrasion between the metal pin and the frontal stroke stop 94 of the guide member 67, a metal disc can be placed on the stroke stop 94. In the case of a pressure movement of the metal pin of the actuating shaft 47 strikes the metal disc.

On the retaining flange 69 is according to the FIG. 3b on the circumferential side a projecting portion 95 is formed, which has a mounting opening 97. Like in the FIG. 4 is shown, the mounting opening 97 is aligned with a corresponding mounting opening 98 of an elongated printed circuit board 99. Through the mounting opening 98 and the thus aligned mounting opening 97 on the guide element 67, a not shown connecting element can be inserted. The printed circuit board 99 is therefore to be connected to the retaining flange 69 of the guide element 67 without great installation effort. On the printed circuit board 99, the switches 51 and the operation indicators 21 are mounted. As a result, a compact set of components comprising the switches 51, the printed circuit board 99, the operating displays 21, the guide elements 67 with the gas flaps 47 is achieved in a simple assembly manner.

Claims (10)

1. Gas cock for a gas burner (1, 3, 5, 7) of a gas cooker hob, with an actuating shaft (47), which is mounted in a housing (57) of the gas cock to be rotatable and/or axially displaceable and which is connected with a control knob (13, 15, 17, 19) for exerting a rotary and/or press movement on the actuating shaft (47), which is led out of the gas cock via a passage opening (63) of a cover part (59) of the housing (57), and a guide element (67), which is associated with the gas cock and which guides substantially free of play the actuating shaft (47) protruding out of the cover part (59), characterised in that the guide element (67) is constructed with a mounting flange (69) for mounting additional components and that the mounting flange (69) of the guide element (67) is formed with at least one recess (77, 79) enabling access to a bypass nozzle (81, 83) of the gas cock.
2. Gas cock according to claim 1, characterised in that the guide element (67) is constructed as an axially elongated guide sleeve.
3. Gas cock according to claim 1 or 2, characterised in that the guide element (67) consists of plastics material.
4. Gas cock according to any one of the preceding claims, characterised in that the mounting flange (69) is constructed for mounting additional components in the form of a circuitboard (99) and/or switch (51) and/or light-emitting diode display (21).
5. Gas cock according to any one of the preceding claims, characterised in that the guide element (67) is constructed with at least one fastening element (71) for fastening to the gas cock housing (57).
6. Gas cock according to any one of the preceding claims, characterised in that a switch cam (87) which is constructed in such a manner that on rotation of the actuating shaft (47) a switch (51) is activated is fastened to the actuating shaft (47) and the switch (51) is connected with an electric control device (33) in order to conduct a corresponding signal to the electrical control device (33).
7. Gas cock according to claim 6, characterised in that the switch (51) is mounted on a circuitboard (99).
8. Gas cock according to claim 7, characterised in that the switch cam (87) is rotatably mounted on the guide element (67).
9. Gas cock according to claim 7 or 8, characterised in that the guide element (67) comprises a stroke abutment (94) which in the case of a press movement exerted on the actuating shaft (47) forms an abutment for the actuating shaft (47) with its switch cam (87).
10. Gas cooker hob with at least one gas burner (1, 3, 5, 7) as well as a gas cock according to any one of the preceding claims.

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