Multi-gas valve for a gas burning appliance

Abstract

.[.The cooking appliance (1) having a control panel (2) is equipped with one or more gas flow (Q) regulating valves, wherein the rotary regulating plug (6) is provided with various peripheral through holes (16-19). The control knob (9) being interchangeable for fitting to the actuating shaft (7), is chosen from the two units available, one and the other permitting different angular limit positions of the regulating plug (6) for the supply of a constant minimum gas flow Qmin, adjusted each one for a different type of gas N gas or LP gas. The outlet conduit (5) of the valve is equipped with a further injector nozzle (21,23) for adjusting a constant gas flow Qmax to be fed into the conduit (25) of the correspondent burner, when the cooking appliance is supplied with a LP gas..]. .Iadd.A valve adapted to regulate the flow of both a natural gas and a liquefied petroleum gas. According to one implementation the valve includes a valve body having a rotatable regulating organ positioned between a valve inlet and a valve outlet, the valve outlet having a first restriction and a second restriction successive to the first restriction, the first restriction including a first hole calibrated to provide a given maximum flow rate of the natural gas at a first pressure in the absence of the second restriction, the second restriction removeably attached to the valve outlet, the second restriction including a second hole calibrated to provide a given maximum flow rate of the liquefied petroleum gas at a second pressure..Iaddend.

Claims

.[.1. A valve comprising: a valve body having a rotatable regulating organ positioned between a valve inlet and a valve outlet, the regulating organ configured to vary the flow rate of the gaseous fuel at the valve outlet as a function of an angular position of the regulating organ, a first angular position of the regulating organ determines a first minimum flow rate of a natural gas, and a second angular position of the regulating organ, successive to the first angular position, determines a second minimum flow rate of a liquefied petroleum gas, a control knob used to manipulate the angular position of the regulating organ coupled to the regulating organ by an actuating shaft, the control knob having a feature to prevent rotation of the regulating organ beyond the first angular position, absent the presence of the feature on the control knob the regulating organ is rotatable to the second angular position, the valve outlet having a restriction that determines a maximum flow rate of the natural gas..].

.[.2. A gas burning appliance adapted for a supply of natural gas and liquefied petroleum gas to a burner comprising: at least one regulating valve with a valve body, the valve body having a rotatable regulating organ operationally coupled to an actuating shaft that protrudes from a control panel of the cooking appliance, the regulating organ positioned between a valve inlet and a valve outlet and configured to vary the flow rate of the gaseous fuel at the valve outlet as a function of an angular position of the regulating organ, a first angular position of the regulating organ determining a first minimum flow rate of the natural gas, and a second angular position of the regulating organ, successive to the first angular position, determining a second minimum flow rate of the liquefied petroleum gas, a control knob attached to the actuating shaft useable to manipulate the angular position of the regulating organ, the control knob having a feature that cooperates with a part of the appliance other than the valve to prevent rotation of the regulating organ beyond the first angular position, the regulating organ rotatable to the second angular position successive to the first angular position absent the presence of the feature on the control knob, the valve outlet having a restriction that determines a maximum flow rate of the natural gas..].

.[.3. The gas burning appliance of claim 2 wherein the feature of the control knob projects from a base of the control knob facing the control panel and travels within a groove in the control panel, the groove having an end corresponding to the first angular position..].

.[.4. The gas burning appliance of claim 2 wherein the actuating shaft has associated with it an engagement feature that cooperates with a part of the valve to impede rotation of the regulating organ beyond the second angular position..].

.Iadd.5. A valve adapted to regulate the flow of both a natural gas and a liquefied petroleum gas comprising: a valve body having disposed therein a rotatable regulating organ positioned between a valve inlet and a valve outlet, the valve outlet having a first restriction and a second restriction successive to the first restriction, the first restriction comprising a first hole calibrated to provide a given maximum flow rate of the natural gas at a first pressure in the absence of the second restriction, the second restriction removeably attached to the valve outlet, the second restriction comprising a second hole calibrated to provide a given maximum flow rate of the liquefied petroleum gas at a second pressure, the second hole being smaller than the first hole, the regulating organ being configured to vary the flow rate of the gaseous fuel at the valve outlet as a function of an angular position of the regulating organ, a first angular position of the regulating organ determines a first minimum flow rate of the natural gas, and a second angular position of the regulating organ, successive to the first angular position, determines a second minimum flow rate of the liquefied petroleum gas, the valve further comprising a stop that prevents rotation of the regulating organ beyond the second angular position..Iaddend.

.Iadd.6. The valve according to claim 5, wherein the first restriction is formed within a press-in disc that is pressed in the valve outlet..Iaddend.

.Iadd.7. The valve according to claim 6, wherein the first restriction is formed within a press-in disc that is pressed in the valve outlet..Iaddend.

.Iadd.8. The valve according to claim 6, wherein the first restriction is formed within a threaded disc that is threaded in the valve outlet..Iaddend.

.Iadd.9. The valve according to claim 5, wherein the first restriction is formed within a press-in disc that is pressed in the valve outlet..Iaddend.

.Iadd.10. The valve according to claim 5, wherein the first restriction is formed within a threaded disc that is threaded in the valve outlet..Iaddend.

.Iadd.11. The valve according to claim 5, further comprising a control knob used to manipulate the angular position of the regulating organ coupled to the regulating organ by an actuating shaft, the control knob having a feature to prevent rotation of the regulating organ beyond the first angular position, absent the presence of the feature on the control knob the regulating organ is rotatable to the second angular position..Iaddend.

.Iadd.12. A gas burning appliance adapted for a supply of natural gas and liquefied petroleum gas to a burner, the gas burning appliance comprising: at least one regulating valve with a valve body, the valve body having disposed therein a rotatable regulating organ operationally coupled to an actuating shaft that protrudes from a control panel of the cooking appliance, the rotatable regulating organ positioned between a valve inlet and a valve outlet, the valve outlet being in fluid communication with the burner, the valve outlet having a first restriction and a second restriction successive to the first restriction, the first restriction comprising a first hole calibrated to provide a given maximum flow rate of the natural gas at a first pressure in the absence of the second restriction, the second restriction removeably attached to the valve outlet, the second restriction comprising a second hole calibrated to provide a given maximum flow rate of the liquefied petroleum gas at a second pressure, the second hole being smaller than the first hole, the regulating organ being configured to vary the flow rate of the gaseous fuel at the valve outlet as a function of an angular position of the regulating organ, a first angular position of the regulating organ determines a first minimum flow rate of a natural gas, and a second angular position of the regulating organ, successive to the first angular position, determines a second minimum flow rate of a liquefied petroleum gas, the valve further comprising a stop that prevents rotation of the regulating organ beyond the second angular position..Iaddend.

.Iadd.13. The gas burning appliance according to claim 12, wherein the second restriction is removeably attached to the valve outlet by a threaded connection..Iaddend.

.Iadd.14. The gas burning appliance according to claim 13, wherein the first restriction is formed within a press-in disc that is pressed in the valve outlet..Iaddend.

.Iadd.15. The gas burning appliance according to claim 13, wherein the first restriction is formed within a threaded disc that is threaded in the valve outlet..Iaddend.

.Iadd.16. The gas burning appliance according to claim 12, wherein the first restriction is formed within a press-in disc that is pressed in the valve outlet..Iaddend.

.Iadd.17. The gas burning appliance according to claim 12, wherein the first restriction is formed within a threaded disc that is threaded in the valve outlet..Iaddend.

.Iadd.18. The gas burning appliance according to claim 12, further comprising a control knob attached to the actuating shaft useable to manipulate the angular position of the regulating organ, the control knob having a feature that cooperates with a part of the appliance other than the valve to prevent rotation of the regulating organ beyond the first angular position, the regulating organ rotatable to the second angular position successive to the first angular position absent the presence of the feature on the control knob..Iaddend.

.Iadd.19. The gas burning appliance according to claim 18, wherein the feature of the control knob projects from a base of the control knob facing the control panel and travels within a groove in the control panel, the groove having an end corresponding to the first angular position..Iaddend.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a sectional view of a gas valve according to the invention, fitted on a panel of a cooking appliance.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

(2) In reference to FIG. 1, an embodiment of a gas cooking appliance 1 such as a barbecue comprises a control panel 2 on which are mounted one or more rotary gas valves 3 of the type with a frustro-conical regulating plug 6. The cooking appliance 1 may be of two types in respect of the type of gas supplied, natural gas (NG) or liquefied gas (LPG) from the external source—GAS IN—through a valve inlet conduit 4 in the valve body 3a. Each one of the valves 3 mounted on the panel 2 is always of a single type, all with a same valve body 3a and regulating plug 6. The inlet flow “Q” is transmitted to an internal chamber 8 in regulating plug 6 in communication with an outlet conduit 5 in the valve body 3a. The regulating plug 6 rotates around a central axis 10 actuated by shaft 7 for the supply of the flow “Q”, which is directed towards a burner inlet duct 25 on the appliance, being the latter specifically adapted to either N gas or LP gas supplying.

(3) The valve body 3a has an elongated shape with a frusto-conical central housing cavity 15, wherein the regulating plug 6 is pushed by a spring 11 for a tight sealing. The free end of the actuating shaft 7 is installed passing through a hole 2a in the appliance panel 2, and afterwards the user fits it with a control knob 9, which is chosen from the two different units of control knob 9, both supplied to the user with each valve unit 3. A cover or valve cap 12 protecting the housing cavity 15, has a tubular bushing 12b for guiding the actuating shaft 7 in rotation.

(4) The regulating plug 6 may rotate with the shaft 7 an angle “A” in either of the two directions from an initial angular position “zero” degrees corresponding to the valve closed condition “OFF”, to an angular position “A” between 90.degree. and 270.degree. The OFF position is the initial end of the rotational travel “A”, and it is established for example by a radial pin 13 on the shaft. The cover 12 presents a sliding surface for the radial pin 13, up to a recess 12a in the cover acting as a stop for the rotation of the radial pin 13.

(5) In reference to the valve embodiment represented in FIG. 1, from the angular position OFF rotating in a clockwise direction, the frusto-conical plug 6 may regulate the supply of different gas flows, a maximum flow “Qmax”, a minimum “Qmin” and an intermediate flow “Qint” between the Qmax and the Qmin, in function of the rotated angle “A”. A constant minimum flow “Qmin” of the N gas must be higher than a “Qmin” of the LP gas, when supplied to a respective burner in both cases of the same power. In function of whether N or LP gas is supplied to the cooking appliance, the control knob 9 to be fitted on the actuating shaft 7 is distinguished for example by means of a lug 14 integral with the control knob. The control knob 9 represented on the appliance in FIG. 1 is adapted for the supply of N gas, having a protuberance or lug 14 projecting from a knob base 9a facing the panel 2. The second type of control knob 9 having not the protuberance 14, is chosen for its mounting on a cooking appliance that uses LP gas.

(6) The regulating plug 6 rotates to a determined angular position for the supply of a maximum flow “Qmax” of either NG or LPG on both types of cooking appliance 1. The Qmax inflow is regulated by a through hole 16 in the regulating plug, facing the inlet conduit 4. If the regulating plug 6 is rotated further, an intermediate flow “Qint” will be supplied through a groove which has a decreasing area. In accordance with the angle rotated, a through hole 18 or a through hole 19 for a “Qmin” flow is facing the inlet conduit 4 at an ensuing angular position different from one another depending on the gas supplied to the valve, N gas or LP gas respectively. Diameter of each one of holes 18 and 19 are calibrated for the correspondent supply of a Qmin.

(7) When installed on the panel 2, the control knob unit 9 chosen for the supply of LPG, this has no lug 14 or any other element for limiting the angle “A” of rotation. Thus, the regulating plug 6 may rotate as far as an angular position of 270 degrees. The cover 12, provided with the tubular portion 12b for guiding the valve shaft 7, and said recess 12a for limiting said longer angular travel corresponding to the LP gas Qmin, is made economically by die-stamping operations only. The economical cost of moulding two types of control knob 9, with and without integral lug 14 for guiding its rotation, is also low.

(8) Besides that described above, other embodiments of the regulating passage openings 18,19 for the different values of Qmin are possible. Half of the control knob 9 units of the kind applied to the NG appliance, may be manufactured with some integrated guiding means 14 on the control knob 9, and interact with some part of the cooking appliance 1 associated with the panel 2, for example a running slot 20 in a panel wall, in order a limit position to be arranged of rotation travel other than that imposed by the actuating shaft.

(9) The arrangement of the two different stop means 12a and 20, respectively in the valve body 3a and on the control panel 2, each one with a pre-set circular extension, matches up with the two angular travels “A” corresponding to that of the two hole passages 18 and 19 for supplying a constant NG Qmin or a constant LPG Qmin. In this way, a single valve unit 3 is used, without having to make any adjustment, valid for any type of gas supplied to the cooking appliance 1.

(10) The burner of the cooker appliance (not represented in the drawing), supplied by the valve unit 3, is placed with its feed conduit 25 facing the valve outlet conduit 5. The space of air apart from the burner conduit 25 permits the fuel mixture 26 of primary air with the Qmax flow of outgoing gas from the valve 3 for injection into the burner feed conduit 25.

(11) In accordance with the type of gas, N gas or LP gas, in order to provide the valve 3 with means for adjustment and injection of the Qmax gas flow outgoing from the regulating plug 6, the valve outlet conduit 5 has a press-in or threaded disc 21 inserted for the restriction of the Qmax flow through a calibrated central hole 22, which permits the passage of a given Qmax flow of N gas, substantially higher than the Qmax of LP gas which it is necessary to inject into the burner of the same output. The restrictor disc 21 remains fitted on the valve all the time irrespective of the type of gas used. When the cooker appliance 1 is supplied with LP gas, it is necessary to restrict the outgoing Qmax flow so as to adapt the output of the burner, so the valve outlet conduit 5 is also fitted with an injection nozzle 23, threaded manually into the mouth of the conduit 5, and it has a calibrated hole 24 for a given Qmax flow of LP gas, substantially smaller than the hole in the restrictor disc, the latter secured in a manner valid for the passage of a Qmax both of N gas and of LP gas.

(12) Thus, by means of the interchangeable control knob 9 and the installation or otherwise of the injection nozzle 23, all the cooker appliances, whether they be N gas or LP gas, are fitted with the same valve units 3 without the need to make any flow regulating adjustment. Together with the valve unit 3, the user receives a kit containing two different control knob units 9, easily distinguishable from each other, and an injection nozzle 23. In accordance with the type of gas used, the user chooses one of the controls 9 for manual installation on the actuating shaft 7, and also decides whether or not to install the injection nozzle 23, which is also fitted manually for the injection of LP gas without the need for tools.