GB2075660A - A gas fitting, especially for heaters and boilers - Google Patents

Abstract

A gas fitting for controlling and regulating heaters and boilers is provided with a safety valve at a gas passage opening (22), the movable closure member (32) of which is acted upon by a closing spring (88) and a magnetic operating member (90) of an ignition safeguard based on the ionisation principle. This operating member (90) is formed as a push magnet and is arranged spatially in front of the opening to the gas passage remote from the valve seat (30). The space in the fitting housing receiving the closing spring and bounding the opening in the gas passage on the valve seat is so dimensioned that a magnet insert of a thermo-electric ignition safeguard can be accommodated in the said space. By these measures, the gas fitting can be combined both with a thermo-electric ignition safeguard and an ignition safeguard operating on the ionisation principle wherein, in both cases, substantially one and the same housing can be used and this housing need only be matched to the magnet insert smaller in diameter than the magnet operating member. <IMAGE>

Description

SPECIFICATION A gas fitting, especially for heaters and boilers State of the art The invention originates from a gas fitting according to the preamble to the main claim.

One gas fitting is already known (German OS 2422 319) in which the magnetic operating member for the ignition safeguard based on the ionisation principle is formed as a pull magnet and is arranged spatially in front of the opening on the valve seat side in a gas passage monitored by the safety valve. With many fittings, it is desirable, according to requirements, to provide a magnetic operating member for an ignition safeguard operating on the ionisation principle or to provide a magnet insert for a thermo-electric ignition safeguard and moreover to retain the other operational elements of the fitting, such as for example, a pressure regulator and a thermostatic regulating valve as well as as many as possible of the other parts of the fitting unaltered.When, with the known fitting, the pull magnet is replaced by a commercial magnet insert for a thermo-electric ignition safeguard, this occurs at the location of the pull magnet whereby its operating element projects upwardly out of the housing of the fitting. Moreover, it must be noted that, for one and the same size of fitting, a commercial magnet insert for a thermo-electric ignition safeguard is smaller than the magnetic operating member for a safeguard operating on the ionisation principle because, as is known, the magnet insert only retains the safety valve in the open position, but the magnetic operating member must move the closure member into the open position.Thus, when in connection with the known arrangement, a housing is to be provided which can be used for both kinds of ignition safeguard, this must be matched to the larger diameter of the pull magnet so that, when using a magnet insert for a thermoelectric ignition safeguard, it is in itself too large.

Advantages of the invention As opposed to this, the arrangement in accordance with the invention comprising the characterising features of the main claim has the advantage that the housing can be matched to the smaller megnet insert for the thermo-electric ignition safeguard. When using the fitting in apparatus comprising ionisation monitoring, its larger magnetic operating member, which in accordance with the invention is formed as a push magnet, can be arranged outside the housing at the location of the omitted operating elements for the magnet insert so that the size of the housing is not influenced by the dimensions of the operating member.

Drawing An embodiment of the invention is illustrated in the drawing and is described in detail in the following specification. The two figures each show a cross-section through a gas fitting which, in Fig. 1, is provided with a magnet insert for a thermo-electric ignition safeguard and in Fig. 2 is provided with a magnetic operating member for an ignition safeguard based on the ionisation principle.

Description of the embodiment The gas fitting has a housing consisting of three parts 10, 1 2, 14 and on which is mounted at the top cover 1 6 of plastics material. A union 1 8 provided with an internal screwthread and behind it a gas inlet union (not visible in the drawing) both of which lead to a chamber 20 between the housing portions 10 and 12, are formed on the housing portion 1 0. The chamber 20 is connected through a passage 22 to a chamber 24 between the housing portions 1 2 and 14 from which a duct 26 leads to a pressure regulator (not visible in the drawing) and a thermostatic control valve and then to a main gas line.The pressure regulator and the control valve are included in the gas fitting, their housing being extended for this purpose in a direction extending perpendicular to the plane of the drawing. From the chamber 24, a further duct 28 leads to a union for an ignition gas line (not shown).

The passage 22 is surrounded by a valve seat 30 which is monitored by a closure member 32 which, together with the valve seat 30, forms an ignition safety valve. The ignition gas flowing away through the duct 28 is controlled solely by the ignition safety valve 30, 32. A magnetic valve can be incorporated in the main gas line connected to the duct 26, which magnetic valve retains the main gas line closed, for example, in the rest position and maintains the main gas line open during energisation. An electric switch 34 for controlling the magnetic valve is provided on the housing portion 14 and has a nomally closed contact and is actuable by an operating member for the illustrated ignition safety valve formed as a see-saw 36 described in more detail below.

The closure member 32 is displaceably mounted on a switching tappet 38 which in its turn is displaceably guided in the housing portion 1 4 and is under the influence of a spring 40 which urges the switching tappet 38 upwards into the illustrated position in which a flange 42 on the switching tappet 38 engages an abutment 44 fixed to the housing.

The abutment 44 supports a weak spring 46 which engages the closure member 32 and attempts to urge the latter into the open position.

A knife bearing 50 is formed on the hous ing portion 12 against which is retained a- double armed tiiting lever 52 by means of. a counter bearing 54- fixed to the housing bore tion 1 2. One end of the tilting lever 52. is provided with two prongs 56 of a fork which engage the rim 58 of the closure member 32.

A- closing spring- 60 which is supported by a knife bearing 62 formed on the housing parts tion 12, engages the -other end of the tilting lever 52 for å snap action. In the illustrated position, the closing spring 60 urges a clockwise torque on the tilting lever 52 whereby the prongs 56 of the fork on the- tilting lever are- sup-ported by the valve seat 30 through the closure member 32. On forcing the switching tappet 38 downwards and opening the valve, the tilting lever 52 is pivoted anti-clockwise whereby the tilting lever is forced through an unstable position beyond which the closing spring. 60 pivots the tilting lever snap-wise into its other limit posi- tion.

The valve has a second switching tappet 64 which is displaceably guided in the housing portion 14 and carries a flange 66 which limits the downwards rnoxsement of the switching tappet 64. The see-saw 36 pivotally mounted about the pin 68 is associated with the two switching tappets 38 and 64 as a common actuating member and projects upwardly beyond the cover 1 6 and has two dperating surfaces 72 and 74 which are- asso- ciated with the two switching tappets 38 and 64. Furthermore, the see-saw 36 is provided with a web 76 which, on pivoting the seesaw anticlockwise, actuates the switch 34.

A so-called magnet insert 80 is arranged doaxially with respect to the closure member 34 of the valve and is connectable through a union 82 to a thermo-element which can be heated by an ignition flame supplied through the duct 28. The magnet insert 80 is screwed into the union 1 8 and the armature of the magnet insert 80 is connected through a pin 84 to a plate 86 which, when the magnet is not energised, is forced by a spring supported by the housing of the magnet insert 80 against the cldsure member 32. The spring 88 is so designed that, on its own, it applies the closing force for the valve against the force of the Spring 46.

In the illustrated position, the valve is closed. In order to set the apparatus in operation, the see-saw 36 is pivoted anticlockwise whereby its working surface 72 engages the switching tappet 38 and moves the latter downwards. In so doing, the closure member 32 is raised from its valve seat, the armature engages the pole of the magnet insert through the plate 86 and the tilting lever 52 is pivoted to such an extent that it tilts under the influence of the closing spring 60 into its other limit position in which it is supported on the housing through the switching tappet 64 and a safety disc 90 mounted thereon.Simultaneously, the electric. switch 34 is actuated whereupon the magnetic valve connected. in the- supply line to the main burner of the apparatus is closed and the gas flowing through the valve 30, 32 can only flow through the duct 28 to the ignition burner.

When the ignition flame has heated the thermo-ele-ment the see-saw 36 can be released whereupon- the spring 40 moves the see-saw 36 back into its central position in which the working surface 72 lies in the plane illustrated by the dotted line 92. The closure member 32 does not take place in this return movement because, unhindered by the tilting lever 52, it is retained in the open position by the spring 46 and the armature of the magnet insert 80 adhering to the poles. With the return movement of the see-saw 36 into the illustrated central position, its web 76 is also raised from the switch 36 whereupon the magnetic valve in the main gas line is opened.

Thereafter, the gas can flow through the pressure regulator and the thermostatic control valve to the main burn.er of the apparatus.

If the ignition flame is extinguished accidentally and the thermo-element is then cooled to a particular extent, the armature is released from the poles of the magnet insert 80 whereupon the spring 88 urges the closure member 32 onto its valve seat 30 against the force of the spring 46 and thus interrupts the gas supply to the main burner. When the valve is to be closed deliberately, the see-saw 36 is pivoted clockwise whereby its working surface 74 moves the switching tappet 64 downwards and the latter pivots the tilting lever 52 over its unstable central position whereupon the closing spring 60 transfers the tilting lever completely into the illustrated limit position.

In this position, the closing spring 60 then provides the closing force for the valve on its own until the armature of the magnet insert 80 is released and its return spring 88 acts in addition on the closure member 32 in the closing sense.

With the construction of the gas fitting according to Fig. 2, a magnetic operating member 90 of an ignition safeguard based on the ionisation principle is used instead of the magnet insert 80 and the operating members for the ignition safety valve. All the other functional parts of the fitting and its housing portions remain just the same so that a simplified accomodation is provided. In the region of the union 1 8 formed without any internal screwthread, the housing portion 10 is provided with a complete base section 92 on which is supported a closing spring 94 which urges the closure member 96 against the valve seat 30 on the housing portion 12.

When using the gas fitting according to Fig.

1, the base section 92 is removed and the union 1 8 is provided with an internal screwthread so that the magnet insert 80 can be screwed into the housing.

The magnetic operating member 90 is formed as a push magnet the armature 98 of which is connected to a tappet 100 the lower end of which engages a hub-like extension of the closure member 96. The operating member 90 made larger in diameter than the magnet insert 80 (Fig. 1) is arranged outside the fitting housing at its upper end so that the housing can be matched to the smaller diameter of the magnet insert 80. The upper housing portion 14' is provided with a bore 106 for the passage of the tappet 100 and a bore 108 coaxial thereto for centering the magnet core 110 of the operating member 90. At its upper end, the housing portion 14' has a collar 11 2 which surrounds a sealing element 114 for sealing the bore 106.

The magnetic operating member 90 is surrounded by a cover 11 6 made of plastics material which is fixed to the housing by locking means (not shown). As with the arrangement according to Fig. 1, the housing is extended in a direction extending perpendicular to the plane of the drawing and accommodates a pressure regulator and a thermostatic control valve. Additional means for fixing an electric control apparatus can be provided on the outer wall of the housing and which monitors the energising current for the operating member 90 and if necessary a further magnetic valve in series with the ignition safety valve.

Claims (2)

1. A gas fitting, especially for heaters and boilers, comprising a safety valve at an opening of a gas passage the movable closure member of which is influenced by a closing spring and a magnetic operating member of an ignition safeguard operating on the ionisation principle and which transfers the closure member into the open position after the occurrence of an ignition flame, characterised in that, the magnetic operating member of the ignition safeguard is formed as a push magnet and is arranged spatially in front of the opening to the gas passage remote from the valve seat, and that the space in the fitting housing receiving the closing spring and bounding the opening to the gas passage on the valve side is so dimensioned and its wall region lying coaxially opposite the valve seat is so designed that a magnet insert of thermo-electric ignition safeguard can be inserted in the said space and can be fixed to the said wall region.

2. A gas fitting substantially as herein described with reference to Fig. 1 or Fig. 2 of the accompanying drawings.