Gas valve

Abstract

The present patent prescribes a new “GAS VAL VE”, according to which the valve, instead of having two different internal components that work with only one type of gas feed each, now has internally a component that simultaneously works with two types of gas, being that for such, one simply needs to change its position on the inside of the valve.

Description

[0001] The present patent is for a new “GAS VALVE”, being that such valve is to be used in stove burners in general.

[0002] As is technically known, gas stoves have pressure valves in their burners operated by respective control knobs on the front panel of the device, which enable them to open, close and regulate the amount of gas going to the burners, consequently obtaining low and high flames.

[0003] In some stove models, the seal of the aforesaid valves occurs through an elastic disk seal, which works against a metal seal seat. In these valves, because of the fact that the disk seal works under axial pressure against the aforesaid metal seat, the same quickly wears down and becomes bent, mainly at the contact points with the seat, causing the formation of leak points, thus requiring periodic replacement.

[0004] In other stove models, valves are the “conical male” type, i.e., they are made up of a metal rod with a conical end, able to rotate inside a similarly conical metal seat, said rod being equipped with orifices whose alignment and nonalignment with an orifice in the seat determines the valve's opening and closing. In these valves, because of the fact that the seal is also made through constant radial pressure between the conical rod and the conical seal seat, there is no problem with the quick wearing down mentioned above; however, because they are two metal pieces that are in surface contact, the seal between them leaves a lot to be desired, being relatively assured by a layer of grease, which disappears over time, likewise causing leaks, and consequently requiring constant maintenance servicing.

[0005] More recently, the metal conical seal seat was replaced by an elastic conical seal seat, which, as it is made out of a resilient material, started to provide a much safer seal against the conical metal rod, without needing to use grease. In these valves, it is very difficult for the resilient seal seat to become bent, thus providing better tightness for the assembly, and a substantially longer valve life, without needing to replace parts or needing periodic maintenance servicing.

[0006] Such solution was the content of patent BR PI 8500156-2, filed on Jan. 14, 1985, of the same Applicant, in the which the conical metal rod is equipped, on the side, with two orifices having different diameters, whose alignment with an orifice in the elastic seal seat determines the passage of a greater or smaller amount of gas to the burner, establishing flame regulation, obtaining low and high flames, respectively; when the seal seat orifice is not aligned with either of the rod's orifices, the valve is in closed position.

[0007] Later, another construction was developed in the above described gas valve, according to which, instead of only two possibilities of obtaining flames (high flame and low flame), a progressive variation was obtained between those two positions, allowing users to choose intermediate positions between high and low flames, according to their needs.

[0008] Such solution was the content of patent BR MU 7201189-0, filed on Aug. 4, 1992, of the same Applicant, in the which the progressive regulation of the flame is obtained through a depression on the outside surface of the conical metal rod, being that this depression has a progressively variable height, which determines different areas for gas passage. Thus, there is a totally closed position for the valve, when the open slot on the conical rod is not aligned with the seal seat orifice; there is a totally open position for the valve, when the aforesaid conical rod's open slot is aligned with the seal seat orifice; and from this totally open position, there are intermediate positions, determined to the effect the conical rod is rotated in a counterclockwise direction, since the gas passage section (area) restricts the flow more and more, until, on reaching the turn limit, minimum flame is obtained.

[0009] In this patent, optionally, a lock is further provided for the position chosen by the user, through the alignment of a lock pin with corresponding depressions on the valve control rod.

[0010] It is also already technically known that gas stoves can be fed by two types of gas, which are GLP (liquid petroleum gas) and natural gas. In the case of natural gas, mains pressure is much lower and the calorific value of the gas is lower, which requires that the gas flow inside stove valves be greater; but in the case of GLP (liquid petroleum gas), pressure is greater and the calorific value is higher, so the gas flow inside the valves must be less.

[0011] In order to meet these two requirements, the stove valves need to undergo modifications on their internal parts; more specifically, the same need to have one of their internal components replaced, depending on the type of gas feed, so as to provide a greater or lesser gas flow.

[0012] Thus being, stoves are usually supplied with a certain type of valve (that works with one type of gas feed), which, if necessary, will have one of its internal components replaced (to work with the other type of gas feed). Such replacement is made by the stove manufacturer's own installer at the time the stove is installed in the place where the same will be used, being that, for such, the installer needs to carry out the dismantling of each of the valves, and its subsequent reassembly, this time with the internal component replaced.

[0013] It is thus found that stove manufacturers need to have a suitable installation service, made up of skilled labor, capable of carrying out the necessary changes in the valves of their stoves at the time of installing the same. Also, manufacturers need to keep in stock two different internal components for their valves, one for each type of gas feed.

[0014] Such wedded facts (different components+skilled labor) make up factors that increase the final product cost.

[0015] The present patent prescribes a new “GAS VALVE”, according to which the valve, instead of having two different internal components that work with only one type of gas feed each, now has internally a component that simultaneously works with the two types of gas, being that for such, one simply needs to change its position on the inside of the valve.

[0016] Such component consists of a selector suitably placed inside the cone of the valve control rod, being that such selector is provided with a chamfered reentry on one of its ends, which configures a second channel for gas passage, in addition to the one usually delimited by the internal configuration of the aforesaid cone. Said selector further has a groove in its opposite end, for fitting the tip of a screwdriver, to be introduced by the stove installer through a passage orifice going through the length of the control rod, at the time the position of the aforesaid selector needs to be changed, depending on the type of gas feed in the stove.

[0017] In this manner, when the stove is fed by GLP (liquid petroleum gas), which needs a smaller gas flow, the installer uses a screwdriver to turn the selector in a determined direction up to the maximum limit position determined by a stop, being that this position seals the chamfered reentry on the aforesaid selector, allowing gas passage only through the channel delimited by the actual interior of the cone.

[0018] Conversely, when the stove is fed by natural gas, which needs a larger gas flow, the installer uses a screwdriver to turn the internal selector in the opposite direction, up to the maximum limit position also determined by a stop, being that this position releases the chamfered reentry on the aforesaid selector, delimiting a second channel for gas passage, in addition to the channel delimited by the actual interior of the cone, which provides greater gas flow inside the valve.

[0019] Thus being, the newly innovated selector allows the valve to be regulated for both GLP (liquid petroleum gas) and natural gas, by simply turning the aforesaid part from one side to the other, without needing to replace any parts, and without needing to dismantle and reassemble the valve; consequently, due to the elimination of spare parts, and given the extreme ease of regulation, skilled labor is no longer required for carrying out this service, which substantially contributes to reducing the final stove cost.

[0020] On the other hand, as the selector in question is placed inside the valve, without access from outside, and as the same can be operated only by a conspicuously long screwdriver, there are no risks of the aforesaid selector accidentally or involuntarily being operated, which can only be done intentionally by the stove installer, duly trained for such, thus obtaining complete safety.

[0021] Also, in order to allow for housing this new selector inside the valve cone, the coupling between the cone and control rod was totally redesigned and a completely innovative internal arrangement was developed in order to offer proper transmission of movement between these two parts and safely house the selector, thus avoiding any possible leaks; and such solution resulted in a considerably simpler and more functional design than that of previous valves, further reducing the device's cost.

[0022] Below, the present new valve will be described based on the drawings in annex, through which the same will be better understood:

[0023] FIG. 1 is a blown-up view of the newly innovated valve, being that the cone and selector are illustrated in front and back views for complete visualization of the same;

[0024] FIGS. 2 and 2A illustrate the aforesaid valve in longitudinal and traverse crosscuts, respectively, being that the selector is in the position used when the stove is fed by GLP (liquid petroleum gas) (smaller flow in valve); and

[0025] FIGS. 3 and 3A are the same crosscuts as FIGS. 2 and 2A, this time with the selector in the position used when the stove is fed by natural gas (greater flow in valve).

[0026] The content of the present patent is a “GAS VALVE”. being that this valve is the type made up of a tubular body (1) in the form of a “T,” whose vertical limb (1a), going down, perforates and, by a clamp (1b), is suitably fastened to stove's gas feed pipe (not illustrated), which can be natural gas or GLP (liquid petroleum gas), while the horizontal limb (1c) of the body (1) internally progresses first by a front passage (1d), longer and with larger diameter, followed by two succeeding passages (1e) and (1f), having smaller internal diameters and staggered, progressively expanding, this last configuring the valve's gas output mouth, going towards the respective stove burner.

[0027] The body (1) is equipped with a small upper orifice (1g), in which a corresponding lock pin (2) is put, being that the height is larger than the thickness of the aforesaid body's wall, so as to pass through it and, thus, keep the valve in the position chosen by the user, as explained below.

[0028] Inside the internal passage (1d) of the body (1), there is housed a cylindrical seal seat (3), made out of resilient material and internally conical, equipped with a lower orifice (3a) in alignment with the lower vertical limb (1a) of the body (1).

[0029] On the inside of the aforesaid seal seat (3), there is a metal cone (4), configured by a front disk (4a) from which a subsequent conical passage (4b) projects, whose conical bearing and dimensions match up with the internal conical face of the aforesaid seal seat (3), having an exact fit between the surfaces of both parts.

[0030] The succeeding conical passage (4b) of the aforesaid cone (4) has, on its lateral wall, an open slot (4c), from which a depression (4d) begins on the outside surface of the aforesaid passage, being that this depression covers approximately half of the total surface surrounding the aforesaid cone.

[0031] Suitably coupled to the metal cone (4), there is a metal control rod (5), being that between these two parts there is an expansion spring (6); and constituting how the metal cone (4) and the metal control rod (5) are coupled, the first, starting from its front disk (4a), more specifically from its face opposite to where there is the conical passage (4b), is equipped with two diametrically arranged projections (7) and (7a) having different widths, which fit exactly into corresponding slots (8) and (8a) on the following cylindrical passage (5a) of the control rod (5).

[0032] The body (1) of the valve is closed frontally by a closure part (9), properly fastened to the same; said part (9), in form of a cylindrical cup, has an open bottom (9a), so as to allow passage of the control rod (5) to outside, until it reaches and goes through the stove's front panel, where the usual control knob (not illustrated) for the respective burner is fit on.

[0033] The control rod (5)/cone (4) assembly is able to rotate inside the valve's body (1), more specifically inside the seal seat (3) in its interior; thus, when the user turns the aforesaid control knob on the outside of the stove's panel, the same causes the rod (5)/cone (4) assembly coupled to it to turn, and consequently, the valve to open and close, with release or obstruction of gas passage to the burner as well as regulation of the flame (high and low).

[0034] Depending on the position of the aforesaid rod (5)/cone (4) assembly, the open slot (4c) or depression (4d) of the aforesaid cone either aligns or does not align with the orifice (3a) of the seal seat (3); thus, alignment of the open slot (4c) of the cone (4) with the orifice (3a) of the seal seat (3) causes complete passage of the gas coming from the interior of the vertical limb (1a) of the body (1) to the staggered internal passages (1e) and (1f), and consequently, to the respective stove burner, thus determining maximum flame position; from this position, continuing rotation of the rod (5)/cone (4) assembly, the depression (4d) of the cone (4) then aligns with the aforesaid orifice (3a) of the seal seat (3), causing strangulation of the gas passage area of the limb (1a) to the staggered passages (le) and (1f), and consequently to the burner, now determining minimum flame position; finally, alignment of the flat surface of the cone (4), i.e., without the open slot (4c) or depression (4d) aligned with the aforesaid orifice (3a) of the seal seat (3), causes complete obstruction of the gas passage of the limb (1a) to the staggered passages (1e) and (1f), and consequently to the burner, thus determining the valve's closed position. These positions are appropriately locked by the lock pin (2), as explained below.

[0035] The control rod (5) has a cylindrical passage (5a) that delimits the formation of the three “stop points” (5b) for the valve's lock pin (2), after the same goes through the orifice (1g) of the body (1), thus locking the three positions of the control rod (5) and consequently the valve, in either the completely closed position, maximum flame position or minimum flame position. This is because said lock pin (2), when acting on the aforesaid stop points (5b) of the passage (5a) of the rod (5), impedes the exit of this last depending on the action of the internal spring (6); i.e., the expansion spring (6) contained inside the assembly constantly presses the aforesaid rod (5) outwards, which, however, is impeded from leaving the body (1) by the action of the lock pin (2), which, acting on the cylindrical passage (5a) of the rod (5), impedes the exit of the same.

[0036] The cone (4) delimits the formation of the internal chamber (10), conspicuously small, developed in the three passages with staggered, decreasing internal diameters, being that on the inside of this chamber is where the selector (11) is placed, which constitutes the element responsible for tuning the valve to the natural gas feed position or GLP (liquid petroleum gas) feed position, being that these positions provide greater or lesser gas flow in their interiors, respectively; furthermore there is a seal ring (12) inside the chamber (10).

[0037] Said selector (11), basically cylindrical, is developed in three short passages, a central passage (11a) and two end ones, a back passage (11b) and a front passage (11c), said selector being able to rotate inside the aforesaid internal chamber (10) on a course determined by sliding the tab (13) on the medium passage (11a) in the corresponding circular depression (14) in the cone (4), being that said course is limited by the rim of the aforesaid tab (13) at one end or the other end of the circular shoulder (15), also in the cone (4) as a prolongation of the depression (14), being that these ends configure limiting stops for turning the selector (11) in one direction or the other.

[0038] Said selector (11) has a chamfered reentry (16) in its back passage (11b), which, depending on the selector's position, may or may not be aligned with a minuscule slanted orifice (17) set in the cone (4).

[0039] Thus, when the selector (11) is turned to the limit established by the tab shoulder (13) at one of the stops, the aforesaid chamfered reentry (16) does not align with the aforesaid orifice (17) in the cone, which is, consequently, sealed, so that the gas then goes exclusively through the channel delimited by the actual internal configuration of the aforesaid cone (4) (FIGS. 2 and 2A). In this position, gas flow inside the valve is smaller, thus being indicated for when the stove is fed by GLP (liquid petroleum gas).

[0040] Conversely, when the selector (11) is turned to the limit established by the tab shoulder (13) at the other stop, the aforesaid chamfered reentry (16) now aligns with the aforesaid orifice (17) in the cone, delimiting both the formation of a second gas passage channel and the one usually delimited by the internal configuration of the aforesaid cone (4) (see FIGS. 3 and 3A). In this position, gas flow inside the valve is greater, thus being indicated for when the stove is fed by natural gas.

[0041] Said selector further has a groove (18) in its opposite front passage (11c) for fitting the tip of a screwdriver, to be introduced by the stove installer through a passage orifice (19) going through the control rod (5), at the time the position of the aforesaid selector (11) needs to be changed, depending on the type of gas feed in the stove.

[0042] In this manner, when the stove is fed by GLP (liquid petroleum gas), which needs a smaller gas flow, the installer uses a screwdriver, introducing it through the passage orifice (19) of the rod (5) and fitting it in the groove (18) of the internal selector (11), in a determined direction up to the maximum limit position determined by the shoulder stop (15), being that this position seals the chamfered reentry (16) on the aforesaid selector, allowing gas passage only through the channel delimited by the actual interior of the cone (FIGS. 2 and 2A).

[0043] But, when the stove is fed natural gas, which needs a larger gas flow, the installer uses a screwdriver to turn the internal selector (11) in the opposite direction, up to the maximum limit position also determined by the other shoulder stop (15), being that this position releases the chamfered reentry on the aforesaid selector, delimiting a second channel for gas passage, in addition to the channel delimited by the actual interior of the cone, which provides greater gas flow inside the valve (FIGS. 3 and 3A).

[0044] Thus being, with the newly innovated valve, it is now possible to regulate the valve (1) for both GLP (liquid petroleum gas) and natural gas, by simply turning the internal selector (11) from one side to the other, without needing to replace any parts, and without needing to dismantle and reassemble the valve; consequently, due to the elimination of spare parts, and given the extreme ease of regulation, skilled labor is no longer required for carrying out this service, which substantially contributes to reducing the final stove cost.

[0045] On the other hand, as the selector in question (11) is placed inside the valve (1), without access from outside, and as the same can be operated only by a conspicuously long screwdriver, there are no risks of the aforesaid selector accidentally or involuntarily being operated, which can only be done intentionally by the stove installer, duly trained for such, thus obtaining complete safety.

[0046] Also, in order to allow for housing this new selector (11) inside the valve cone (4), the coupling between the cone (4) and control rod (5) was totally redesigned and a completely innovative internal arrangement was developed in order to offer proper transmission of movement between these two parts and safely house the selector (11), thus avoiding any possible leaks; and such solution resulted in a considerably simpler and more functional design than that of previous valves, further reducing the device's cost.

Claims

1) “GAS VALVE”, being that this valve is the type made up of a tubular body (1) in the form of a “T,” whose vertical limb (1a) perforates and, by a clamp (1b), is fastened to stove's gas feed pipe, which can be natural gas or GLP (liquid petroleum gas), characterized in that by the horizontal limb (1c) of the body (1) progresses by three staggered internal passages (1d), (1e) and (1f), this last configuring the valve's gas output mouth, going towards the respective stove burner; said body (1) is equipped with a small upper orifice (1g), in which a corresponding lock pin (2) is put; inside the body (1), there is housed a cylindrical seal seat (3), made out of resilient material and internally conical, equipped with a lower orifice (3a) in alignment with the lower vertical limb (1a) of the body (1); exactly on the inside of the aforesaid seal seat (3), there is a metal cone (4), with an open slot (4c) and depression (4d), and suitably coupled to the metal control rod (5), being that between these two parts there is an expansion spring (6); the cone (4) is equipped with two diametrically arranged projections (7) and (7a) having different widths, which fit into corresponding slots (8) and (8a) on the following cylindrical passage (5a) of the control rod (5); there is a closure part (9), with an open bottom (9a), for passage of the control rod (5) to outside, until it reaches and goes through the stove's front panel, where the usual control knob for the respective burner is fit on; the control rod (5) has a cylindrical passage (5a) that delimits the formation of the three stop points (5b) for the valve's lock pin (2), after the same goes through the orifice (1g) of the body (1), thus locking the three positions of the control rod (5) and consequently the valve, in either the completely closed position, maximum flame position or minimum flame position; the cone (4) delimits the formation of the internal chamber (10), conspicuously small, developed in the three passages with staggered, decreasing internal diameters, being that on the inside of this chamber is where the selector (11) is placed, surrounded by a seal ring (12), which constitutes the element responsible for tuning the valve to the natural gas feed position or GLP (liquid petroleum gas) feed position; said selector (11), basically cylindrical, is developed in three short passages, a central passage (11a) and two end ones, a back passage (11b) and a front passage (11c), said selector being able to rotate inside the aforesaid internal chamber (10) on a course determined by sliding the tab (13) on the medium passage (1a) in the corresponding circular depression (14) in the cone (4), being that said course is limited by the rim of the aforesaid tab (13) at one end or the other end of the circular shoulder (15), also in the cone (4) as a prolongation of the depression (14), being that these ends configure limiting stops for turning the selector (11) in one direction or the other; said selector (11) has a chamfered reentry (16) in its back passage (11b), which, depending on the selector's position, may or may not be aligned with a minuscule slanted orifice (17) set in the cone (4), either delimiting or not delimiting the formation of a second gas passage channel, in addition to the one usually delimited by the internal configuration of the aforesaid cone (4); said selector further has a groove (18) in its opposite front passage (11c) for fitting the tip of a screwdriver introduced through a passage orifice (19) going through the control rod (5), at the time the position of the aforesaid selector (11) needs to be changed, depending on the type of gas feed in the stove.