GB2189578A

GB2189578A - Gas tap assembly

Info

Publication number: GB2189578A
Application number: GB08709619A
Authority: GB
Inventors: Masahiko Komura; Hiroshi Ito; Masanori Shimizu
Original assignee: Rinnai Corp
Current assignee: Rinnai Corp
Priority date: 1986-04-26
Filing date: 1987-04-23
Publication date: 1987-10-28
Anticipated expiration: 2007-04-23
Also published as: HK32991A; CN87102974A; JPS62180266U; CN1009307B; GB2189578B; GB8709619D0; JPH0424310Y2

Abstract

In a gas tap assembly with stop, ignition and fully open positions provided by cooperation between a cover plate projection 11 and a cam surface 12 on a turning member 7, and between a protrusion 14 on the turning member and a groove 13 in a connecting member 10, an operating shaft (5) has at least one additional operating position serving as a simmering flame position. The connecting member (10) is provided with an engaging member (20) projecting therefrom, and a bent member (21) is arranged to be brought into abutment with the engaging member (20) when the operating shaft (5) is operated to turn to the ignition position. The bent member (21) projects from a cover plate (6b) so that there is left a gap l larger than the thickness of the engaging member (20), between the cover plate (6) and the bent member (21). A stop portion (22) on the cam surface (12) is arranged to be brought into abutment with the projection (11) when the operating shaft (5) is operated to turn to its simmering flame position. <IMAGE>

Description

SPECIFICATION Gas tap assembly This invention relates to a gas tap assembly mainly for use in a domestic gas cooking stove.

An assembly of this type is described in Japanese Utility Model Kokai Showa 58(1983)-93670 (and in Figs. 17 and 18 herein). In this assembly, between a closure member b located at a lower position and turnably housed in a main body a and an operating shaft d which is located at an upper position and is turnabiy inserted through a cover plate c provided on an upper surface of the main body a, there is provided a turning tube f which is movable downwards against the action of a spring e and is in turning engagement with the upper end of the closure member b.The turning tube f is provided on its upper surface with an inclined cam surface h which is in slidable engagement with a projecting member g projecting downwards from the cover plate c, A connecting member j, which is movable downwards against the action of a spring i and is in turning engagement with a lower end portion of the operation shaft d, is provided in the turning tube f, and is brought into engagement, at a protrusion k provided on its outer surface, with a vertical guide groove la downwardly directed step portion 1-1 in the turning tube f so that if the operating shaft d is operated to turn from its stop position, the protrusion k is brought into engagement with the downwardly directed step portion 1-1 to cause a turning movement of the turning tube f and hence a lowering thereof, and thereby the connecting member j is lowered and an electromagnetic safety valve n provided below it is pushed open.

This conventional assembly, however, is inconvenient in that the operation of the closure member b is changed over from its closing position to only two positions, namely an ignition position and a fully open position. It is desirable with this type of apparatus to have at least one additional operational position serving as a simmering flame position, and, in this case, it is also desirable to stop reliably the closure member b not only at the ignition position, but also at the simmering flame position for supplying an extremely small amount of gas.

This invention has the object of providing an assembly meeting this desire. Thus, in an assembly of the type wherein a main body having a cover plate and housing an electromagnetic safety valve and a closure member is provided with an operating shaft arranged to be operated to turn from its stop position to its ignition position and its fully open position so as to form an assembly, and there is provided between the closure member and the operating shaft a turning tube which is movable downwards against the action of a first spring and is in turning engagement with the closure member, and a connecting member which is so provided in the turning tube as to be movable downwards against the action of a second spring and is in turning engagement with the operating shaft, and the turning tube is provided on its upper surface with a cam surface for being in slidable engagement with a projection member projecting downwards from the cover plate, and the connecting member is in engagement, at a protrusion on an outer surface thereof, with such a vertical guide groove with a downwardly directed engaging stage portion that is made in the turning tube so that if the operation shaft is operated to turn from its stop position on its ignition position, the protrusion may be brought into engagement with the downwardly directed engaging stage of the guide groove, resulting in causing a turning movement of the turning tube and a lowering movement of the same in accordance therewith, whereby the electromagnetic safety valve may be pushed to open and at about the same time an ignition means may be operated, and if the operation shaft is released from operation at its ignition position, the operation shaft may be turned back slightly by the action of the second spring for being changed over to its fully open position, it is characterized in that for the operation position of the shaft there is provided at least one additional operation position serving as a simmering flame position, and the connecting member is provided with an engaging member projecting therefrom, and a bent member which is arranged to be brought into abutment with the engaging member when the operating shaft is operated to turn to the ignition position is so projected from the cover plate that there may be left a gap larger than the thickness of the engaging member between the cover plate and the bent member, and a stop portion which is arranged to be brought into abutment with the projection member when the operating shaft is operated to turn to its simmering flame position is formed on the cam surface.

For a better understanding of the invention, reference will now be made, by way of example, to the drawings in which: Figure 1 is a sectional side view of one embodiment of a gas tap assembly of this invention; Figure 2 is a top plan view thereof; Figure 3 is a sectional side view thereof showing the operational condition thereof when the operating shaft thereof is turned to its ignition position; Figure 4 is an exploded perspective view thereof; Figures 5a-5e and Figures 6a-6c are diagrams for explaining the operations thereof; Figures 7-12 are sectional views taken along lines VIl-VIl to XIl-XlI of Fig. 1; Figure 13 is a diagram for explaining the operation of a click stop mechanism; Figure 14 is a diagram for explaining respective changeover operations of the operating shaft;; Figure 15 is a diagram for explaining the burning conditions of respective burners at respective operating positions; Figure 16 is a diagram the changeover conditions of a closure member thereof; Figure 17 is a sectional view of a conventional gas tap assembly; and Figure 18 is an exploded perspective view thereof.

When an operating shaft 5 is operated to turn from it stop position as shown in Fig. 5a and Fig. 6a to its ignition position as shown in Fig. 5b and Fig. 6b, firstly a connecting member 10 is turned therewith, and accordingly a turning tube 7 is given a turning movement by the connecting member 10 such that a protrusion 14 is in engagement with a downwardly directed step portion 1 3a of a guide groove 13.

By the turning movement of the operating shaft 5, the turning tube 7 is lowered against the action of a first spring 8 in accordance with the turning of the shaft 5, and the connecting member 10 is also lowered against the action of a second spring 9 due to engagement of the protrusion 14 with the step position 13a, to obtain the condition shown in Fig. 5b.

During this operation, the closure member 4 is turned by the turning movement of the turning tube 7, and a gas outlet opening 2c for a pilot gas burner A, a gas outlet opening 2b for a main gas burner B, and a gas outlet opening 2b for a slow or simmering gas burner C, are brought into their open positions.

At the same time an ignition means 16 is operated, and a safety valve 3 is pushed open by the foregoing lowering of the connection member 10, whereby the pilot burner is ignited.

It, then, the operating shaft 5 is released from operation, the protrusion 14 is released from its engagement with the step portion 1 3a and is permitted to move upwards along the guide groove 13, and is moved upwards together with the connecting member 10 by the resilient force of the spring 8 as shown in Fig. 5c. Thus the safety valve 3 is released from being pushed, and at the same time the operating shaft 5 is turned back to its fully open position owing to the fact that the shaft is urged upwards by the spring 8, and the protrusion 14 is moved upwards to slide along on the step position 13a.

The foregoing operation is not particularly different from that of the conventional device as disclosed in the foregoing Japanese Utility Model Kokai Showa 58(1983)-93670.

According to the present invention, in the foregoing conventional device, the connecting member 10 is provided with a projecting member 20 projecting outwards therefrom, and a bent abutment member 21 which is adapted to be brought into abutment with the projecting member 20 at the foregoing lowered position is provided on the cover plate 6 so that a gap I which is larger than the thickness of the projecting memer 20 is left between the cover plate 6 and the bent member 21.

Accordingly, when the operating shaft 5 is operated to turn from its stop position, as shown in Fig. 6b, the projecting member 20 is brought into abutment with the bent member 21 so that the operating shaft 5 is stopped reliably. If, however, the operating shaft 5 is released from being held by the hand of an operator at that position, the engagement of the protrusion 14 with the step position 13a is released and thereby the connecting member 10 is moved upwards as mentioned before, so that the abutment between the bent member 21 and the projecting member 20 is released.

Accordingly, this makes it possible for the closure member 4 to be turned further by the operating shaft 5, i.e. to a larger angularlyrotated position, and this makes it possible to turn the operating shaft 5 to its simmering flame position. If the operating shaft 5 is turned to the simmering flame position, the projecting member 11 is brought into abutment with a stop portion 22 formd on the cam surface 12 so that it can be assured that the operating shaft 5 is stopped at this position. In this position the gas outlet opening 2b for the main gas burner is closed and thus there is obtained a simmering flame condition.

One embodiment of this invention will now be described with reference to the drawings.

Referring to the drawings, numeral 1 denotes a tap assembly comprising a main body 2 containing therein an electromagnetic safety valve 3 and a closure member 4, and having an operating shaft 5 arranged to be operated to turn from its stop position to its ignition position and its fully open position. Numeral 6 denotes a cover plate fixed to the main body 2. There is provided, between the closure member 4 and the operating shaft 5 of the main body 2, a turning tube 7 which is movable downwards against the action of a first spring 8 and is in turning engagement with the closure member 4. A connecting member 10 is provided in the turning tube 7 so as to be movable downwards against the action of a second spring 9 and is in turning engagement with the operating shaft 5. The turning tube 7 is provided on its upper surface with a pair of cam surfaces 12 which are adapted to be brought into slidable engagement with respective ones of a pair of projecting members 11 projecting downwards from the cover plate 6. The turning tube 7 is provided in its peripheral side surface with right and left vertical guide grooves 13 each having a downwardly directed stop portion 13a, and a pair of protrusions 14 projecting outwards from the connecting member 10 are engaged therewith, so that if the operating shaft 5 is operated to turn from its stop position to its ignition position, and the protrusion 14 is brought into engagement with each of the downwardly directed step portions 1 3a of the guide grooves 13 to cause a turning movement of the turning tube 7 and a lowering movement thereof in accordance therewith.In acordance with the turning movement of the turning tube 7, an operating rod 15 extending through the closure member 4 is lowered, and thereby the electromagnetic safety valve 3 is pushed open and at about the same time an ignition means 16 provided on the cover plate 6 is operated.

Thereafter, if the operating shaft 5 is released from operation at the ignition position, and the operating shaft 5 is urged by the foregoing first spring 8 so as to be turned back slightly thereby changing it from its ignition position to its fully open position.

The turning engagement between the connecting member 10 and the operating shaft 5 is effected by means of an engaging pin 14a transversing the inner peripheral surface of the connecting member 10 formed into a tubular one, which is brought into engagement with a slot 5a in the lower end of the operating shaft 5. Additionally, the turning engagement between the turning tube 7 and the closure member 4 is effected by leg members 7a projecting downwards from the turning tube 7 and brought into engagement with vertical slots 19 in the upper end of the closure member 4. The engaging pin 14a and the pair of protrusions 14 are formed of a single member extending through the tubular connecting member 10.

The foregoing arrangement is not particularly different from that of the conventional assembly.

According to the present invention, in addition to the foregoing items, the operating shaft 5 has additional operating positions, namely a simmering flame position as an additional position and further, as an occasion demands, a weak flame position. For this purpose, there is provided on the connecting member 10 an engaging member 20 projecting therefrom. A bent abutment member 21 which is arranged to be brought into abutment with the engaging member 20 when the operation shaft 5 is turned to its ignition position is provided on the cover plate 6 so that a gap I which is larger than the thickness of the engaging member 20 is left between the cover plate 6 and the bent member 21. There is provided on the cam surface 12 a stop portion 22 arranged to be in abutment with the projecting member 11 when the operating shaft 5 is turned to the simmering flame position.

In more detail, as shown in Fig. 14, for instance, the ignition position is situated as a position advanced by 115 degrees counterclockwise from the stop position, the fully open position is situated at a position turned back slightly therefrom, that is at a position advanced by 95 degrees from the stop position, the simmering flame position is situated at a position advanced by 55 degrees from the fully open position, that is at a position advanced by 150 degrees from the stop position, and the weak flame position is situated at a position turned back by 50 degrees from the fully open position, that is at a position advanced by 45 degrees from the stop position.

If, thus, the operating shaft 5 is turned from the stop position to the ignition position, the electromagnetic safety valve 3 is pushed open as mentioned before, and the closure member 4 is turned together with the operating shaft 5, and, as shown in Fig. 16d, a gas inlet opening 2a in the main body 2 is brought into communication with a gas outlet opening 2b for a main gas burner B through a first passage opening 4b having a large diameter and diverging from a main gas passage 2A in the closure member 4. The gas inlet opening 2a and a gas outlet opening 2c for a pilot flame burner A are brought into communication one with another through a pilot gas valve 30 provided in the main gas passage 2A and a pilot gas passage 4e connected to the main gas passage 2A.Additionally, the gas inlet opening 2a and a gas outlet opening 2d for a simmering flame burner C are brought into communication one with another, through a third passage 4d diverging from the main gas passage 2A.

Thus, the gas inlet opening 2a is brought into communication with all of the gas outlet openings 2b, 2c and 2d so that all of the burners A, B and C are supplied with gas, as shown in Fig. 15b, and are ignited by the ignition means 16. Also, if the operating shaft 5 is moved to the fully open position, the communication of the gas inlet opening 2a with all of the gas outlet openings 2b, 2c and 2d is kept as it is, as shown in Fig. 16c, and the condition shown in Fig. 15b is kept as it is.

When the operating shaft 5 is turned to the simmering flame position, the communication between the first passage 4b and the gas outlet opening 2b for the main burner B is cut off, as shown in Fig. 16e, and there is obtained a condition wherein gas is burned only at the pilot flame burner A and the simmering flame burner C as shown in Fig. 15c. If the operating shaft 5 is changed over to the weak flame position, the gas outlet opening 2b is brought into communication with the gas inlet opening 2a through a second passage opening 4e having a small diameter, as shown in Fig.

16b, so that the amount of gas passing there through is decreased to obtain å burning condition as shown in Fig. 15a.

The electromagnetic safety valve 3 is interposed between the gas inlet opening 2a and the main gas passage 2A. As stated above, the safety valve 3 is arranged so as to be pushed open by the operation rod 15 when the operating shaft 5 is at the ignition position, and so that after being released from being pushed when the operating shaft 5 is released from operation so as to return to the fully open position, it is kept open by the electromotive force of a thermocouple (not shown) adapted to be heated by the pilot flame burner A.

Although the operating shaft 5 is regulated in position at the ignition position and at the simmering flame position, as mentioned above, it is not regulated in position at the fully open position or at the weak flame position.

Accordingly, in the illustrated example, a click stop mechanism 23 is interposed betwen the operating shaft 5 and the cover plate 6 for obtaining a click stop action at each of the foregoing two positions Thus, the clickstop mechanism 23 is such that, as shown in Fig.

11, the operating shaft 5 is provided with a turning plate 25 which is provided with first and second slits 24a and 24b inclined in relation to the radial direction so that the two slits 24a and 24b are displaced one from another by about 180 degrees. The turning plate 5 is additionally provided with first and second balls 26a and 26b movable along the respective slits 24a and 24b.A resilient plate 28 having two balls openings 27a and 27b for receiving respectively the first ball 26a in the first slit 24a and a single ball opening 27c for receiving the second ball 26b in the second slit 24b, is placed over the upper surface of the turning plate 25 and is fixed to the cover plate 6, so that a click stop action may be obtained by virtue of the fact that, in the course of the turning operating shaft 5, either one of the balls 26a and 26b is received in at least one of the ball openings at respective positions This operation will now be explained with reference to Fig. 11 and Fig. 13.

If, now the operating shaft 5 is operated to turn from the stop position toward the ignition position, which is the position facing point X on the resilient plate 28, as shown in Fig. 11 and Fig. 13a, the second ball 26b in the second slit 24b is first received in the ball opening 27c and is then removed from the ball opening 27c. As a result, the turning operation of the shaft 5 to the ignition position can be performed.

When the ball 26b reaches the ignition position, the operating shaft 5 is released by the operator so that the shaft 5 alone is returned to the fully open position, due to the presence of gap Y between the turning plate 25 and the operating shaft 5 and due to the presence of the second spring 9. If the operating shaft 5 is then turned from that fully open position to the weak flame position, as shown in Fig.

11 and Fig. 13b, the first ball 26a in the first slit 24a is received in the ball opening 27a to set the shaft 5 at the weak flame position. If the operating shaft 5 is turned from the weak flame position to the fully open position, as shown in Fig. 13c, the second ball 26b in the second slit 24b is received in the third ball opening 27c to again set the shaft 5 at the fully open position. Furthermore, if the operating shaft 5 is then turned from the fully open position to the simmering flame position so as to reach the stop position, as shown in Fig.

13c, the first ball 26a is received in the ball opening 27b. If, furthermore, the operating shaft 5 is turned back from the simmering flame position to the fully open position, as shown in Fig. 13d, the first ball 26a in the first slit 24a is received in the ball opening 27c, so that the shaft 5 is set at the fully open position. If, then, the shaft 5 is turned back from that position to the weak flame position, as shown in the same Figure, the ball 26a is received in the ball opening 27a, so that the shaft 5 is set at the weak flame position The ignition means 16 comprises a piezoelectric means attached to the upper surface of the cover plate 6. The ignition means 16 is constructed so that a hammer 1 6c facing a piezoelectric element 16b is caused to strike the element 16b by means of a cam plate 16a provided on the operating shaft 5.This is not particularly different from the prior art. Instead of the ignition means of the piezoelectric type, there may be used an ignition means of the type wherein an electric spark discharge is produced. In this case, it is sufficient for a switch interposed in an spark discharging circuit to be closed at the ignition position of the shaft 5 or a position slightly on this side of the ignition position.

An illustrated example, the apparatus has a pilot burner A of a standing burner type, but this pilot burner A can be replaced by a pilot burner of the type that is ignited only when the shaft 5 is moved to the ignition operation.

Alternatively, the pilot burner may be removed and the main gas burner may be ignited directly.

In the illustrated example, the cover plate 6 consists of two plates, namely upper and lower cover plates 6a and 6b, and the projection member 11 projects from the upper cover plate 6a and the bent member 21 is provided on the lower cover plate 6b. However, the cover plate may consist of a single plate.

In the illustrated example, lest the operating shaft 5 be operated mischievously by children or the like, there is provided a preventative means. Thus, a pin 29 to engage a cutout portion 1 7a in a stop member 17 is provided on the operating shaft 5 so that the operating shaft 5 may be turned only when the shaft 5 is pushed against the action of a spring 18 interposed between the pin 29 and the cover plate 6 whereby the pin 29 is disengaged from the cutout position 17a.

In the illustrated example, the engaging member 20, the bent member 21 and the stop portion 22 are provided in pairs.

Thus, according to this invention, as for the operating positions of the operating shaft, there is provided, in addition to the conventional operating positions, at least one position serving as a simmering flame position, and a connecting member is provided with an engaging member projecting therefrom and a bent member which is to be brought into abutment with the engaging member at the ignition position of the operating shaft is so provided on the cover plate that a gap which is larger than the thickness of the engaging member is left between the cover plate and the bent member, and additionally the stop portion which is to be brought into abutment with the projection member when the operating shaft is operated to turn to the simmering flame position is provided on a cam surface in a turning tube. Consequently there can be produced easily, by addition of a comparatively simple construction, a gas tap assembly in which the operating shaft can turn by a comparatively large angle of rotation and can be stopped accurately at the ignition position and at the simmering flame position.

Claims

1. A gas tap assembly of the type comprising a body having a cover plate and housing a safety valve and a closure member provided with an operating shaft adapted to be operated to turn from a stop position to an ignition position and to a fully open position; there being provided between the closure member and the operating shaft a turning member which is movable downwards against the action of a first spring means and is in turning engagement with the closure member; a connecting member being provided in the turning member so as to be movable downwards against the action of a second spring means and so as to be in turning engagement with the operating shaft; the turning member being provided with a cam surface adapted to be in slidable engagement with a projection member projecting downwards from the cover plate; the connecting member being in engagement, at a protrusion provided on an outer surface thereof, with a guide groove having a stop portion in the turning member so that if the operating shaft is operated to turn from is stop position to its ignition position, the protrusion is brought into engagement with the step portion of the guide groove resulting in a turning movement of the turning member and consequently in a lowering movement of the turning member whereby the safety valve is pushed open and at about the same time an ignition means is operated, and so that if the operating shaft is released from operation at its ignition position, the operating shaft is turned back by the action of the second spring means to its fully open position; wherein the operating shaft has at least one additional operating position serving as a simmering flame position and the connecting member is provided with an engaging member projecting therefrom, wherein an abutment member arranged to be brought into abutment with the engaging member when the operating shaft is operated to turn to the ignition position projects from the cover plate so that there is left a gap larger than the thickness of the engaging member between the cover plate and the abutment member, and wherein a stop portion arranged to be brought into abutment with the projection member when the operating shaft is turned to its simmering flame position is formed on the cam surface.

2. An assembly as claimed in claim 1, wherein the operating shaft has a further operating position serving as a weak flame position.

3. An assembly as claimed in claim 1 or 2, wherein the ignition position is situated as a position advanced by about 115 degrees from the stop position, the fully open position is situated at a position advanced by about 95 degrees from the stop position, the simmering flame position is situated at a position advanced by about 150 degrees from the stop position, and the weak flame position (if present) is situated at a position advanced by about 45 degrees from the stop position.

4. An assembly as claimed in any of claims 1 to 3, wherein a click stop mechanism is interposed between the operating shaft and the cover plate so that the operating shaft may be given a click stop action at the fully open position and (if present) at the weak flame position.

5. An assembly as claimed in claim 1, substantially as hereinbefore described with reference to, and as shown in, Figs. 1 to 16 of the drawings.