GB2024991A

GB2024991A - Improvements Relating to Gas Taps

Info

Publication number: GB2024991A
Application number: GB7828918A
Authority: GB
Original assignee: Ewarts Ltd; Cannon Industries Ltd
Current assignee: Ewarts Ltd; Cannon Industries Ltd
Priority date: 1978-07-05
Filing date: 1978-07-05
Publication date: 1980-01-16
Also published as: NZ190303A; AU526758B2; AU4554579A; GB2024991B

Abstract

The gas tap distributes gas in symmetrical fashion to a selected number of burners, so that either the central burner (alone) is supplied with gas, or two burners one on each side of the central burner is supplied, or three burners is supplied including the central burner, and so on. The tap has a plurality of radial ports opening from a central supply bore 62 in a rotary conical plug 56 and which communicate with a series of outlet passages 64, 66, 68 through the body accommodating the plug, so that by a series of angular increments of movement different combinations of the passages are connected to the bore. <IMAGE>

Description

SPECIFICATION Improvements Relating to Gas Taps This invention relates to taps for controlling the flow of gas.

The invention is particularly concerned with appliances such as gas fires where the burning gas heats one or more ceramic panels to red heat.

The panels radiate the heat and give an aesthetically advantageous "warm glow" effect.

However, when less heat output is required, and the gas supply is reduced, the panels may be reduced below red heat, and whilst they continue to radiate in the infra-red, the aesthetic effect is lost. It is therefore known to provide separate panels with individual burners, and to provide low and high heat settings in which a different number of the burners are supplied with gas, so that each panel is effectively either on or off.

The aims of the invention are firstly to provide an improved tap which facilitates this, and secondly in a preferred version, which enables a set of several burners to be controlled so that in intermediate heat settings the supplied burners are symmetrically located; that is to say, assuming for example that five burners are provided, to enable any number of burners between 1 and 5 to be supplied according to the tap setting, and so that when one only is supplied it may be the centrally positioned one of the set of five, when two are supplied, it will be one on each side of the central one, and so on.

In accordance with the invention, a gas tap comprises a plug rotatable in a complementary bore in the body, a gas inlet, a plurality of gas outlets from the body, and a series of ports and passages in the plug and opening from the bore, whereby the plug may be turned between a first position in which there is no flow from any outlet, through a position in which the flow may be from one outlet, at least one further position in which said one outlet is cut off, but flow is established through a second or further outlet, to a position in which flow occurs through all of the outlets.

In some circumstances it may be required to allow for a bleed flow of gas at all times, for example to maintain a pilot light burning, and in a tap designed to meet such a requirement, the term "no flow" or equivalent is to mean that either the outlet in question is completely closed, or it only opens sufficiently for the bleed flow.

Preferably the arrangement is provided with so-called automatic ignition device (which may be an alternative to the constant pilot light referred to above) and may be arranged for this purpose so that the tap is to be turned on fully before the ignition device is operated, and the latter may direct a spark to a central one of a line of burners to ignite the corresponding one of the issuing gas jets, allowing the flame to spread to the others.

If desired, the ports and passages may be dimensioned so as to allow a slight overlap during the turning of the plug which redirects the flow of gas, so that where one or more of the burners are to be extinguished, the flame there continues for sufficiently long to enable the newly introduced burners to be ignited.

In accordance with a second aspect of the invention a gas tap as earlier defined is provided with an associated distribution block whereby at least one of the outlets from the tap may be connected to a plurality of individual burners.

In accordance with another aspect of the invention, a gas tap together with a distribution block, as hereinbefore defined, is assembled to a support member provided with a plurality of burners or burner supply ports and with the distribution block connected to the individual burners or parts by corresponding pipes.

One presently preferred embodiment of the invention is now more particularly described by way of example only, and with reference to the accompanying drawings wherein: Figure 1 is an elevation of an assembly; Figure 2 is a plan view of that assembly; Figure 3 is a sectional elevation of the tap forming part of the assembly of Figure 1 on a larger scale; Figure 4 is a sectional plan view on the line 4 of Figure 3; Figure 5 is an elevation of the plug for the tap; Figures 6, 7 and 8 are sections on the line 6 6, 7-7, and 8-8 of Figure 5; and Figures 9 to 14 show cross-sections of the plug of Figure 5 in the positions of Figures 6, 7 and 8 in each case, indicating the relative positions in each six different angular locations of the plug relative to the body of the tap.

Referring now to the accompanying drawings and particularly Figures 1 and 2 thereof, the arrangement comprises a gas tap 20 assembled to a distributor block 22 which is carried by a structural rail 24 which mounts z series of burner supply ports 26, 28, 30, 32 and 34. As best seen in Figure 2, the outer ports 26, 34 are connected by relatively long pipes 38 to the distribution block, the inner ports 28, 32 are connected by relatively short pipes 36 to the distribution block, and the central port 30 is directly connected to the distribution block without any intervening pipe. The pipes may be of copper tube brazed to the burner part in each case, and each part will be associated with further burner structure such as a jet block as required; parts illustrated may be called injector holders.

Turning now to Figure 3, this particularly shows the spindle 40 which is connected to an operating rod or cable (not shown) terminating in a convenient position on the appliance remote from the tap.

The assembly may be associated with a piezoelectric ignition device (not shown) and the arrangement is that when the spindle 40 is rotated through a particular angle which serves to turn on the gas supply fully to all of the jets, the device is actuated to initiate an igniting spark.

Alternatively a pilot light system could be employed.

Figure 3 of the drawings shows the body of the tap providing an end inlet 54 opening to a frusto conical bore which seats an angularly movable plug 56. The latter is connected to the spindle via a niting device with a spring 58 urging the plug to seat in the frusto-conical bore and spring 60 urging the niting device. The plug has an axial bore 62 which opens to the inlet 54 and a series of radial passages opening to the plug/bore interface and which will be more particularly described hereinafter. The body includes (in this instance) three separate outlet passages 64, 66, 68 which are parallel and have their axes contained in a common plane radial to the axes of the body bore and the plug.These passages terminate in the manifold block 22 which (see Figure 4) includes extension slots 70, 72. The slot 70 communicates the outlet passage 64 with the first longitudinally extending passage 74 which connects with pipes 38 and the slot 72 communicates passage 68 with the pipes 36. The central passage 66 is connected axially at 74 for connection to the burner part 30.

Turning now to Figure 5 and Figures 6 to 8, the plug is seen to be provided with three sets of radially extending ports which are spaced along the plug at the same spacing as the passages 64 to 68, and which open between the plug bore 62 and the respective passages 64-68 when the plug is in certain angular positions. The first set of parts 80 are aligned with passage 64, the second set 82 with passage 66, and the third set 84 with passage 68.

Operation of the tap is now explained with reference to Figures 9 to 14. In each of these figures the left hand drawing illustrates the relationship between the plug at the section 6-6 of Figure 5 and the corresponding outlet 64, the right hand drawing illustrates the relationship between the plug at the position of the section 8-8 of Figure 5 with the outlet 68 and the centre drawing shows the relationship at the position of the outlet 66, that is at the section line 7-7 of Figure 5.

Figure 9 shows the positions when the plug is in an "off" position and all gas flow is cut off.

Figure 10 shows when the plug has been rotated through about 2400 in one direction, for example anti-clockwise, for the purpose of operating the ignition device and shows that the plug supplies gas to all three outlets. Hence, all five (in this example) burners are supplied with gas.

Figure 11 shows the position when only four burners are to be supplied, and assumes that the plug is being turned back, that is clockwise, through 450, when outlets 64 and 68 are supplied and outlet 66 is cut-off. Hence, the burner associated with part 30 is cut-off but the other for burners, two on each side of the central burner are still suppled.

In Figure 12, the plug has been turned through a further 450 clockwise which re-establishes communication with the central outlet 66 maintains communication with the outlet 68 and cuts off communication to the outlet 64, so that the central three burners of the line of five are supplied and the other two burners are cut off.

Figure 13 shows the plug turned through a further 450 in the clockwise direction so that again the central burner is cut off, the two adjacent ones are still supplied, and the outer two remain cut-off. Hence two burners will be supplied, one on each side of the central burner.

Figure 14 shows the further position after another 450 of rotation clockwise, when the centre burner is again supplied with gas and all of the others are cut off.

The niting device referred to which is associated with the plug and body, (but could alternatively be associated with the control rod or cable or some extension of the same) facilitates location of the plug in any of the six positions represented by Figures 9 to 14 and possibly prevents the plug coming to rest in any intermediate position. Many forms of niting device including for example spring loaded ball detents, cams and the like are known in the art.

Reference 90 shows a test ripple.

In a modification, not shown, the sets of parts 80 and 84 (but not 82) may be replaced by single radial parts opening to slots in the surface of the plug, to like effect.

Claims

1. A gas tap comprising a plug rotatable in a complimentary bore in the body, a gas inlet, a plurality of gas outlets from the body, and a series of parts and passages in the plug and opening from the bore, whereby the plug may be turned between a first position in which there is no flow from any outlet, through a position in which the flow may be from one outlet, at least one further position in which said one outlet is cut off, but flow is established through a second or further outlet, to a position in which flow occurs through all of the outlets.

2. A tap as claimed in Claim 1 wherein the plurality of outlets have axes included in a common plane radial to the axis of the plug, and the plug has an axial inlet bore and a series of passages opening from the the bore which are respectively located in the same planes normal to the axis as the said outlets.

3. A tap as claimed in Claim 2 wherein a plurality of passages is located in each of the said planes.

4. A tap as claimed in Claim 3 wherein a common plane radial to the axis of the plug contains the axes of one passage in each of said same planes.

5. A tap as claimed in Claim 4 wherein a further common plane radial to the axis of the plug contains the axis of one passage in all but one of said same planes.

6. A tap as claimed in Claims 1 to 5 wherein there are three outlet passages and said same planes contain respectively two three and four outlet passages, arranged to that one passage of the two three and four passages have axes in one common radial plane, a second passage of the three and four passages have axes in a second common radial plane, a second passage of the two passages and a third of the four passages have axes in a third radial plane, and the remaining passages are non-coplanar with any of the others.

7. A gas tap as claimed in any preceding claim provided with an associated distribution block whereby at least one of the outlets from the tap may be connected to a plurality of individual burners.

8. A tap as claimed in Claims 6 and 7 wherein the distribution block is arranged to connect two of the three outlets each to a pair of burners and the third of the outlets to a fifth burner.

9. A tap with a distribution block as claimed in Claim 7 or Claim 8 assembled to a support member provided with a plurality of burners or burner supply supports and with the distribution block connected to the individual burners or parts by corresponding pipes.

10. A gas tap constructed and arranged to operate substantially as described and with reference to the accompanying drawings.