US3070155A - Porland - Google Patents

Description

Dec. 25, 1962 K. PORLAND 3,070,155

THERMO-ELECTRICALLY GAS SHUT-OFF UNIT WITH SAFETY PILOT Filed Feb. 1'7, 1959 2 Sheets-Sheet. 1

Dec. 25, 1962 K. PORLAND 3,070,155

THERMO-ELECTRICALLY GAS SHUT-OFF UNIT WITH SAFETY PILOT Filed Feb. 17, 1959 2 Sheets-Sheet 2 Unite States This invention relates to a thermo-electrically controlled gas shut-off unit with safety pilot, preferably for use in connection with a washing machine or a similar gas comsuming apparatus and of the kind in which the said unit has an inlet valve which in its open position is retained by an electromagnet, the said electromagnet overcoming the action of a spring and receiving current from a thermo element which is in heat transmitting con nection with a pilot burner, and is furthermore provided with a manually operable outlet valve inserted in series with the main burner.

Gas shut-off units of the aforesaid kind are known and they are normally installed in series with an extra shut-off device for the gas piping; the said shut-off device may be designed as a main cock with a plug. Quite apart from the fact that such a main cock is liable to become leaky by very intense use and to become jammed by less intense use, such an extra main cock is a complication since it has to be operated by the user in a definite succession in relation to the pilot burner valve and therefore in many cases is mechanically coupled to the latter, and in any event it means increased cost of the total installation.

It is the object of the present invention to devise a gas shut-off valve in which these drawbacks are eliminated. This is accomplished by the gas shut-oif valve in accordance with the invention thereby that the manually operable outlet valve consists of a spring-loaded disc valve which is coaxial with the inlet valve and has an axially displaceable stern. In the inoperative position of the unit the said disc valve closes a room, which is furthermore limited by the inlet valve and has a discharge opening leading to a pilot burner valve built together with the shut-off unit and inserted in series with the pilot burner, the stem of the outlet valve being adapted to open the inlet valve by displacement in relaticn to the disc of the valve in the direction opposite the direction in which the outlet valve opens.

As a result, an extra shut-off device is rendered superfluous since the outlet valve in the inoperative position of the unit closes the supply to the main burner, but not to the pilot burner, in addition to which the stem may be operated manually so as to open for the gas supply to the pilot burner without simultaneously opening for the main burner of the installation.

According to one feature of the gas shut-off unit according to the invention the disc of the outlet valve is provided with a sealing plate of resilient material which is bent about such edge portion of the disc as faces the stern and is resting in close contact with the stem.

As a result, efiicient sealing between the disc and the spindle is provided, both in the inoperative position of the stem and while it is being displaced.

In accordance with another feature of the gas shut-off unit according to the invention the displacement of the 3,070,155 Patented Dec. 25, 1 962 stern in the direction away from the disc of the inlet valve is limited by a cam disc permanently secured in the easing of the unit and having a working surface facing the inlet valve and cooperating with a guide pin projecting radially from the stem when the stem is turned away from its inoperative position; furthermore, between the disc of the outlet valve and the casing there is provided a closing spring which forces the disc against its valve seat and between a collar provided on the stem and the casing is placed an opening spring which is more powerful than the closing spring and presses the guide pin against the working surface of the cam disc. The said stem has further a contact member cooperating with the disc of the outlet valve so as to displace the said disc when the stem is turned away from its inoperative position.

As a result, the flow area of the outlet valve may be varied by turning the stem in relation to the permanently mounted disc.

In accordance with a third feature of-the gas shut-off unit according to the invention the angular movement of the stem is limited, partly by means of a projection formed on the handle of the stem, partly by means of a stop plate which is mounted on the stem and provided with another projection, the said projections cooperating with a stop placed on the casing.

As a result, the inoperative position of the stem in which the cam disc relieves the stem of the pressure exerted by the opening spring, is well defined thereby that the projection on the handle rests in contact with one side of the stop and that the flow area of the outlet valve may be fixed by means of the projection on the stop plate.

in accordance with a fourth feature of the gas shutoif unit according to the invention the projection on the handle is disposed in such manner in relation to the guide pin of the stern that the said guide pin lies in a first notch in the cam disc when the said projection is resting in contact with one side of the stop, the notch being of such depth that the collar of the stem is clear of the disc of the outlet valve.

As a result, the outlet valve is closed in the inoperative position of the stem and the side edges of the notch press the stern into place in its one extreme position so 0 that the stem can only be removed from the said extreme position by exerting a certain manual force to turn the handle, which provides security in case children should try to operate the handle or if the handle is turned uh intentionally.

In accordance with a fifth feature of the unit according to the invention the cam disc has another notch which is so disposed in relation to the inoperative position of the stem that the guide pin by a predetermined first angular movement of the stern owing to the pressure exerted by the opening spring is forced into the said second notch which is of such a depth that the collar provided on the stem passes the disc of the outlet valve to full opening of the outlet valve. As a result, the said valve admits, on the continued turning of the handle, a full flow of the gas to the main burner of the installation.

In accordance with a sixth feature of the unit according to the invention the cam disc is designed with an oblique surface in such manner that the guide pin, when the handle is turned beyond the aforesaid angular range;

3 passes the disc of the outlet valve towards a minimum flow opening determined by means of the projection on the stop plate.

As a result, the said minimum opening may be adjusted by varying the angle between the projection on the stop plate and the guide pin.

In the unit according to the invention the pilot burner valve is designed as a sleeve valve the slide of which is mounted in a cylindrical bore in the casing of the unit with its axis parallel to that of the inlet and outlet valves.

The result obtained is firstly a suitable compact form of the combined unit and secondly that the operation of the pilot burner valve and the outlet valve becomes very easy and clear; in particular, if the direction of displacement of the said valves from their open to their closed position is alike, for example, so that the operating handles of the two valves, when both burners are alight, are in their top position.

In the unit according to the invention the slide is provided with sealing rings on either side of its closing surface.

As a result, double security against leakage of gas into the atmosphere is obtained in both positions of the safety pilot valve, since the gas, when both the inlet valve and the pilot burner valve are closed, has to pass a sealing surface in the inlet valve and a sealing surface in the pilot burner valve before reaching the atmosphere, whereas the gas, when both the inlet valve and the pilot burner valve are open, has to pass the two sealing rings in the lastmentioned valve before escaping into the atmosphere.

The invention will now be further described with reference to the drawing, in which FIGURE 1 shows a gas shut-off unit in accordance with the invention, viewed in a section on the line I--I of FIGURE 3,

FIGURE 2 is the same, viewed in a section on the line IIII of FIGURE 3,

FIGURE 3 is a top view of the same,

FIGURE 4 is a valve plate for same on an enlarged scale,

FIGURES 5-6 and 11-12 show the handle of the unit in positions corresponding to the characteristic positions of the inlet and outlet valves of the unit,

FIGURES 7-8 and 13-14 are characteristic positions of the cam disc of the unit and of a guide pin controlling the position of the outlet valve,

FIGURES 9-10 and 15-16 show corresponding positions of the inlet and outlet valves.

The drawing shows a gas shut-off unit consisting of a casing 1 with an inlet valve 2 having a valve disc cooperating with a first valve seat and an outlet valve 3 cooperating with a second valve seat, and a pilot burner valve 4. The inlet valve 2 is adapted to be retained in its open position against the pressure exerted by a spring 5 by an electromagnet 6 which in known manner is fed with current from a thermo element (not shown) which is in heat transmitting connection with a pilot burner (not shown) that is connected to a discharge pipe 7. The supply of electric current to the electromagnet 6 from the thermo element takes place through a wire 8. The outlet valve 3 consists of a spring-loaded disc valve mounted coaxially with the inlet valve 2 and supported by an axially displaceable stem 9 which can be operated manually to displace the inlet valve 2 by pressing down a handle 10 mounted on the stem 9. The outlet valve 3 closes in the inoperative position of the gas shut-off unit a space or chamber 11 which is furthermore limited by the disc of the inlet valve 2, which engages with a valve seat 2', and has a discharge opening 12 leading to the pilot burner valve 4 which is built together with the shut-off unit. The disc member of the outlet valve is provided with a sealing plate 13 of resilient material such as rubber or plastic, the said sealing plate being bent around such edge portions of the disc as face the stern and resting in close contact with the stem 9 as shown in FIGURE 4. The displacemeat of the stem 9 in the direction away from the disc of the inlet valve 2 is limited by a cam disc 14 fixed in the casing 1 of the unit and having a working surface facing the direction towards the inlet valve, the said working surface cooperating with a guide pin 15 projecting radially from the stem when the stem 9 is turned away from its inoperative position. Between the disc of the outlet valve and the casing is provided a closing spring 16 which forces the disc against its valve seat 17, and between a collar 18, which is in permanent connection with the stem 9, and the casing 1 is provided an opening spring 19 which is more powerful than the closing spring 16 and forces the guide pin 15 of the stem against the working surface of the cam disc 14 when the stem 9 is turned away from its inoperative position. The turning angle of the stem 9 is limited partly by means of a projection 20 formed on the handle it of the stem and partly by means of a stop plate 21 mounted on the stem 9, the said stop plate being provided with another projection 22, both of the said projections 29 and 22 cooperating with a stop 23 mounted on the casing and of such design that it does not prevent displacement of the handle 10 in the axial direction of the stem 9. The projection 20 of the handle 10 is so disposed in relation to the guide pin 15 of the stem 9 that the guide pin 15 is lying in a first notch 24- of the cam disc 14 when the said projection is resting in contact with the one side of the stop 23, and the notch 24 is of such depth that a shoulder 25 mounted on the stem is clear of the disc of the outlet valve 3. The cam disc 14 has another notch 26 which is so disposed in relation to the inoperative position of the stem 9 that at a predetermined angular movement a of the stem 9 the guide pin 15 owing to the pressure exerted by the opening spring 19 is passed into the other notch 26 of the cam disc. The said notch 26 is of such depth that the shoulder 25 on the stem 9 passes the disc of the outlet valve 3 to a position giving full opening of the outlet valve 3. The cam disc 14 is furthermore so designed with an oblique surface 27 that by continued turning of the handle 10 beyond the aforesaid first angular range a the guide pin 15 passes the disc of the outlet valve 3 towards a minimum opening which is determined by means of the projection 22 on the stop plate 21; the flow area of the said opening may be regulated by varying the angle ,8 between the two projections 20 and 22. FIGURES 5-6 and 11-12 show the position of the handle 10 and FIGURES 7-8 and 13-14 the location of the guide pin 15 in relation to the various parts of the working surface of the cam disc 14, the cam disc in FIGURES 7-8 and 13-14 being shown in its developed state whereas it is, in fact, circular cylindrical. FIGURES 9-10 and 15-16 show such positions of the outlet valve disc in relation to the valve seat 17 and the inlet valve disc in relation to its valve seat 28 as correspond to the positions of the guide pin 15 in FIGURES 7-8 and 13-14.

The pilot burner valve 4 is designed as a sleeve valve the slide 29 of which is placed in a cylindrical bore 30 provided in the casing 1 and having its axis parallel with that of the inlet and the outlet valve. The valve body is provided with a push button 31 serving to effect manual displacement of the slide which in its bottom position closes the discharge opening 12 from the room 11 and in its top position puts the said discharge opening into communication with the discharge pipe 7 for the pilot burner (not shown). The discharge opening 12 is designed as a passage 32 extending transversely of the bore 311 and is closed at its outer end by means of an inserted ball 33. The slide 29 is provided with sealing rings 34 on both sides of its closing surface 35.

The operation of the gas shut-off unit is as follows:

In the closed position of the unit, which is shown in FIGURES 1, 2, 3, 5 and 9, both the inlet valve 2 and the outlet valve 3 are closed, and the pilot burner valve 4 is in its lowermost position as indicated in FIGURE 2 where the closing surface 35 closes the passage 32. The safety system of the pilot burner consists therein that even though a user through a mistake would begin by opening for the feed to the main burner by turning the handle raj from the inoperative position shown in FIGURE 5, in which the projection 20 is resting in contact with the stop 23 and where an O engraved on the handle indicates the neutral position of the handle, to the position shownin FIGURE 11 where a flame engraved on the handle is lying opposite the stop 23, this manipulation will not open to the gas flow, since a gas supply to main burner and pilot burner is impossible because the inlet valve 2 is closed and the pilot burner valve is closed too. The user is hereby reminded of the fact that the pilot burner valve is to be opened by moving the push button 31 upwards, but even this is not sufiicient to cause admission of gas to the pilot burner. The user is hereby reminded of the fact that the handle 1d has to be pressed downwards for a brief interval as indicated by a finger 36 in FIGURE 6 and to be kept down until the pilot burner is lighted, for example by means of a gas lighter or a match. By the downward movement of the handle the stem acts on the stem of the inlet valve, causing the inlet valve to open as indicated in FIGURE 10, whereby the pilot burner is fed with gas from the inlet opening 38 of the unit through the room 11 and the passage 32 and the open pilot burner valve 4. When the pilot burner 4 is alight, the thermo element (not shown) is heated. The said thermo element is in heat transmitting connection with the pilot burner and through the wire 8 the thermo element supplies in the course of 20 seconds such a powerful current to the electromagnet 6 that the latter is capable of retaining an armature 39 mounted on the stem 37 of the inlet valve 2 against the pressure exerted by the spring 5, after which the pilot burner is fed with gas, even though the handle 10 is released and passed upwards by the opening spring 19 so that the guide pin 15, which in FlGURE 8 is indicated in its bottom position, returns to its inoperative position in the notch 24 as indicated in riUURE 7. Meanwhile, if the pilot burner fails to light and the thermo element does not become heated, the armature 39 is not retained by the electromagnet 6, and the inlet valve 2 is again closed by the spring 5. When the pilot burner is alight, the user may by turning the handle 10 from the position indicated in FIGURES 5 and 6 to the position indicated in FIGURE 11 open fully to the main burner, the guide pin 15 being passed into the notch 26 by the spring 19 and the outlet valve being consequently displaced to a maximum extent from its seat 17. The main burner, which is connected to the discharge opening 40 of the unit, is thereby lighted automatically from the pilot burner. The gas supply of the main burner may be varied from fully open as indicated in FIGURE 15 to an adjustable minimum opening as indicated in FIG- URES l2, l4 and 16, the guide pin 15 being, by the turning of the handle 10, caused to slide against the oblique surface 27. This possibility of regulation is indicated on the upper side of the handle by a small engraved flame and an engraved scale. The minimum opening of the main burner is determined thereby that the projection 22 provided on the stop plate 21 cannot be caused to pass by the stop 23. The main burner can be extinguished thereby that the handle is passed from the positions indicated in FIGURES l1 and 12 to its inoperative position, which is shown in FIGURE 5, in which the guide pin 15 absorbs the tension exerted on the stem 9 by the opening spring 15 by resting in the notch 24, whereby the closing spring 16 causes the outlet valve to close, while the pilot burner remains alight, the electromagnet 6 retaining its armature 39, so that the gas supply to the pilot burner is still open. The pilot burner is extinguished by the push button 31 being pressed down to its bottom position, in which the closing surface 35 closes the passage 32, and when the pilot burner is extinguished, the current through the electromagnet is cut oif, after which the spring 5 closes the inlet valve 2. Should the pilot burner be extinguished for one reason or other, for example, owing to a heavy drop of the gas pressure, the thermo element will likewise cease to give current, and after an interval of about 20-25 seconds the electromagnet 6 will release its armature 39 so that the inlet valve 2 is closed.

What I claim and desire to secure by Letters Patent is: 1. A thermoelectricallycontrolled gas shut-off unit for use with gas consuming-apparatus having a main burner and a pilot burner having a thermo element in heat-transmitting relationship therewith, said unit having a casing, an inlet valve in said casing, said inlet valve including a valve stem carrying valve disc, means defining in said casing a first valve seat and a second valve seat, said means defining a chamber between said valve seats, a spring normally maintaining said inlet valve in closed position with said valve disc against said first valve seat, an electromagnet adapted when energized to retain said valve in open position against the action of said spring and receiving current from the thermo element in heat transmitting relationship with said pilot burner, and a manually operable outlet valve in said casing to control the flow of gas to said main burner, said manually operable outlet valve comprising a rotatable axially-displaceable stem carying a guide pin, said last-named stern being aligned with said first-named stem for contact therewith upon downward movement of said last-named stem, a cam member in said casing positioned to be engaged by said pin, a valve disc member surrounding said second-named stern, a closing spring normally urging said disc member against said second valve seat, whereby said outlet vavle is closed in the off position of said unit, an opening spring normally urging said guide pin against said cam member and normally urging said last-named stem away from said second valve seat and away from said first-named stem, said last-named stem having a shoulder positioned to engage said valve disc member to open said outlet valve upon movement of said last-named stem away from said second valve seat and controlling the distance between said member and said seat, said chamber between said first valve seat and said second valve seat having a dis charge passage, and a pilot burner valve in said casing communicating with said passage and thereby with said chamber and controlling flow from said passage to said pilot burner.

2. A gas shut-off unit as defined in claim 1, wherein the valve disc member of the outlet valve is provided with a sealing plate of resilient material which is bent around the edge portion of the valve disc which faces the stem and rests in close contact with the stem.

3. A unit as defined in claim 1, wherein said cam disc has a working surface facing the first valve seat and said guide pin projects radially from the stem, said opening spring being more powerful than the closing spring and said shoulder cooperating with the valve disc member so as to displace said valve disc member when the lastnamed stem is turned away from its inoperative position.

4. A unit as defined in claim 3, further comprising a handle for said last-named stern having a projection, and a stop plate is mounted on the last-named stern and provided with a second projection, a stop carried by said casing cooperating with said projections to limit the angular movement of said last-named stem.

5. A unit as defined in claim 4, wherein said cam disc has a first notch and wherein the projection on the handle is disposed in such manner in relation to the guide pin of the stem that the said guide pin lies in said first notch in the cam disc when said projection is resting in contact with one side of the stop, the notch being of such depth that the shoulder of the stem is clear of the disc valve member of the outlet valve.

6. A unit as defined in claim 5, wherein the cam disc is formed with a second notch disc which is so disposed in relation to the inoperative position of the stem that the guide pin upon a predetermined first angular movement of the last-named stem is forced by the pressure exerted by the opening spring into said second notch which is of such depth that the shoulder provided on the stem moves the disc of the outlet valve to full opening of the outlet valve.

7. A unit as defined in claim 6, wherein the cam disc is formed with an oblique surface in such manner that the guide pin, when the handle is turned beyond said first angular movement,'moves the disc of the outlet valve towards a minimum flow opening determined by the projection on the stop plate.

8. A unit as defined in claim 1, wherein the pilot burner valve comprises a valve slide and a cylindrical bore formed in said casing with its axis parallel to thatof the first and second valve seats, said valve slide being movable in said bore.

9. A unit as defined in claim 8, wherein the Slide is provided with sealing rings on both sides of its closing surface.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Great Britain Aug. 15, 1956

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