US2735483A

US2735483A - Igniter systems for gas ranges

Info

Publication number: US2735483A
Authority: US
Publication date: 1956-02-21
Anticipated expiration: 1973-02-21

Description

1956 A. H. BRODBECK ET AL IGNITER SYSTEMS FOR GAS RANGES 2 Sheets-Sheet 1 Filed Aug. 29, 1951 1956 A. H. BRODBECK ET AL IGNITER SYSTEMS FOR GAS RANGES 2 Sheets-Sheet 2 Filed Aug. 29, 1951 United States Patent (3 IGNITER SYSTEMS FOR GAS RANGES Almer H. Brodbeck, Webster Groves, and Bradley C. Douglas, Kirkwood, Mo., assiguors to Magic Chef, Inc., a corporation of New Jersey Application August 29, 1951, Serial No. 244,142

13 Claims. (Cl. 158-122) This invention relates to igniter systems for gas ranges and with regard to certain more specific features to an electrically controlled system of the class described.

Among the several objects or" the invention may be noted the provision of a low cost, reliable and safe electric igniter system for gas ranges in which a simple initial operation prepares the range for duty; the provision of apparatus in the class described which makes the range completely safe at all times when it is off duty; the provision of apparatus of this class in which a signal is given of any inoperativeness existing whenthe range is on duty; and the provision of apparatus of this class which if an electric power failure occurs may be manually set to operate until the power is restored. Other objects will be in part apparent and in part pointed out hereinafter.

Briefly, the invention consists in a plurality of igniters for a plurality of burners which, when the range is prepared for duty, are all supplied with gas and electric current for operation; otherwise not. Thus (in both forms of the invention shown) when the range is off duty the igniters can never leak gas as sometimes occurs when an igniter constantly supplied with gas is blown out. In one form of the invention the preparation of the range for duty consists in simply turning on one of the control valves which results in supplying gas to all igniters, a pressure switch coming into operation to supply current to all of their ignition coils. In the other form of the invention, the preparatory operation consists in closing a master switch which supplies all of certain igniter coils with current and through an electrical valve supplies gas to all the igniters. In both forms of the invention the igniter coils of the igniters are grounded through igniter switches until ignition has occurred. While grounded the voltage is not applied to a signal lamp; but as soon as ignition has occurred and all igniters are ignited, the grounding switches are all opened and voltage is applied to the signal lamp which then shows that the range is properly prepared for operation of its burners. The signal lamp and the igniter coils, being at this time in series, cause insufiicient voltage to be applied to the coils for them to reach ignition temperature, thus preserving them. For this purpose the signal lamp is designed to operate upon the voltage drop available to it with the ignition coils in series therewith.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of which will be indicated in the following claims.

In the accompanying drawings, in which two of various possible embodiments of the invention are illustrated,

Fig. 1 is an electromechanical diagram of one form of the invention;

Fig. 2 is a similar diagram of a second form of the invention;

Fig. 3 is a horizontal section of one of the control valves of the second form of the invention;

Fig. 4 is a vertical section taken on lines 4-4 of Figs. 2 and 3;

Fig. 5 is a cross section taken on lines 5-5 of Figs. 2 and 3, showing an on position of parts; and

Fig. 6 is a view similar to Fig. 5, showing an off position of parts.

Corresponding parts through out the drawings are indicated by the same reference characters.

Referring now more particularly to Fig. l, numerals 1 indicate burners having control valves 3, ignition ports 5 and ignition flash-back tubes 7. The valves 3 are supplied from a main gas line 9 which is under control of a solenoid-operated gas valve 11. The solenoid coil of valve 11 is indicated at 13. When the coil is unexcited the valve normally closes. It is provided with a manual trip 15 whereby, upon failure of current to the coil 13, the valve may be set to open position. The arrangement is such that when the valve is manually set to open position (upon failure of current into coil 13), any resumption of flow of current cuts out the effect of the trip 15. Valves of this type are known and further description is not necessary. An example of such a valve is one known in the trade as No. 1014-5, sold by McQuay- Norris Manufacturing Company of St. Louis, Missouri. Properties of these valves are that they may be manually tripped to open positions during any off current period but will resume the proper oif-and-on electrical responses after excitation of coil 13.

At numeral 17 are indicated electrical igniters. These are located at the ends of pilot lines 19 extending from the main gas line 9. Lines 19 include adjustable throttles 20. The ends of the pilot lines 19 and the igniters 17 are adjacent the ends of the flash-back tubes 7.

Each ignlter 17 consists of an igniter coil 21, a grounding switch 23 and a thermal link 25 which is exposed to heat from a flame 3 at the end of pipe 19 when the flame is ignited. Each link 25 is anchored at one end to a frame 27 and is joined at the other end to a movable contact of switch 23. The stationary contact of each switch is insulated from the frame 27 as shown at 29. When a flame 43 has been ignited at the end of a pipe 19 by its respective coil 21, the thermal element 25 is heated to open the respective switch 23; otherwise, the thermal element closes the switch.

Sufiicient information has been given in connection with the igniter 17 for complete understanding of the present invention, but if further detail of these are desired, they appear in the U. S. patent application of Bradley C. Douglas and Harry H. Pryor, Serial No. 246,284, filed September 12, 1951, for Electric Pilot- Flame l'gniter and owned by the assignee of this application.

At 31 is shown a transformer on the range, the primary of which is fed from a voltage source 33 through a master control switch 35, also on the range. This switch 35 also controls a supply circuit 37 to the coil 13 of the solenoid valve 11. The secondary of the transformer 31 supplies a circuit 39 in which are serially connected the igniter coils 21 and a voltage-operated pilot signal device such as a signal lamp 41. As Fig. 1 shows, the switches 23 are all connected in parallel with the signal lamp 41.

Operation is as follows:

Assume first that the master switch 35 is open. The

circuits

37 and 39 will then be dead, valve 11 closed, coils 21 and links 25 cold, switches 23 closed and signal lamp 41 out. Since no gas is available through valve 11, no gas can flow either from the pilot tubes 19 or burners 1. The range is then off duty and completely safe and foolproof. For example, the owner may leave the premises without fear of any gas leakage from any blown-out pilot. Small children may tamper with the valves 3 without undesirable results. Switch 35 is placed on the range in a position accessible only to adults.

In order to place the range on duty, the master switch 35 is closed. Assuming that the line 33 is alive,

circuits

37 and 39 will be energized. The former excites coil 13 and opens valve 11, while the latter excites all coils 21 in series, current flowing to ground through any or all closed switches 23. At this time the pilot lamp 41 will be out because, in view of the closed switches 23, there is no voltage across it. Gas now flows from the pipes 19 and is ignited by the glowing coils 21. This heats the links 25 which expand to open switches 23. As soon as all switches 23 are open, the lamp 41 has voltage applied to it in series with the coils 21. The voltage of circuit 39 is then made up of the sum of the voltage drops across the coils 21 and the lamp 41. Under these conditions, the coils carry current but the voltage drop on each is insuflicient to cause them to glow, whereas the lamp is designed to light under its aliquot part of the voltage drop. The gas flowing from pipes 19 is thus ignited and flames 43 burn continuously.

In order to light any burner 1 its respective valve 3 is opened and supplies it with gas. Some of it flows from ignition port 5, passes down to tube 43 and upon flash-back the respective burner is ignited. One or more burners may be turned on and oil at will. When it is desired to throw the range off duty, the switch 35 is opened, whereupon all burners and pipes 19 are deprived of gas by the closing of valve 11. All of the pilot flames 43 are extinguished. The links 25 cool and the switches 23 reclose.

If during on-duty operations any pilot flame 43 goes out, its respective link 25 will cool, reclosing its respective switch 23, thereby removing voltage from the lamp 41 and applying full voltage to the coils 21 which reheat so that the flame 43 that has gone out will relight. During this interval of relighting the signal lamp 41 goes out. If one or more of the igniters 17 should become deranged sulficiently that their flames will not reignite, this condition is shown by the signal light 41 going out. Thus the operator will know that the range is defective and requires repairs. On other words, the range is not in proper condition for operation as to all burners and igniters unless the lamp 41 is lighted.

Sometimes it will occur that a power line such as 33 will fail. In such event the valve 11 may be reopened manually by operating the trip 15. Then the operator can ignite all of the pilots with a match or the like, after which the valve 3 may be operated as usual. Whenever the power line 33 is restored, the valve 11 becomes operative in response to current and the trip returns to its valve-closed position, so that thereafter the stove is under electrical control as long as the line 33 is alive.

Another form of the invention is shown in Figs. 2-6. In this case the burners shown at 51 have control valves 53. The ignition ports are shown at 55 and the flashback ignition tubes at 57. The main gas line is shown at 59. The pilot igniters 17 are the same as those described in connection with Fig. l and therefore carry the same reference characters for identical parts, no further description being required. Each is associated with several ignition tubes 57. The pilot gas pipes 19, having adjustable throttle valves 20, are like those of Fig. l and are adapted to produce a flame 43. As before, a main electric circuit 33 supplies a transformer 31, the secondary of which is connected in a control line 39. As before, the coils 21 are serially connected in the line 39 with a. voltage-operated pilot signal device such as a pilot lamp 41, their switches 23 being grounded and in parallel with the lamp 41.

At 61 is shown a pilot manifold supplying pipes 19 and having a connection 63 with each of the valves 53. It also has a by-pass connection 65 with the gas line 59, in which is a normally closed manual control valve 67. The manifold 61 connects with a pressure switch 62, the pressure-transmitting diaphragm 69 of which controls a 4 switch 71in the line 39. The switch 71 normally biases itself to open position and is closed upon the predetermined pressure in the manifold 61.

Details of the valves 53 are shown in Figs. 3-6. These include inlets 73 from the gas line 59 and outlets 75 to the burners 51. They include outlets 77 to connections 63. Branch passages 79 supply gas from inlets 73 for distribution to

connections

77 and 63. The cores 81 of these valves carry ports 83 forming on-ofi connections between pipe 59 and the outlets 75 to the burners. These cores also carry on-ofl' connections 85 between branches 79 and

connections

77, 63. The arrangement is such (Figs. 5 and 6) that when a control member 87 of a valve 55 is turned counterclockwise, gas will flow from the line 59 first to the pilot manifold 61 and then to the respective burner 51 (see Fig. 5). This raises the pressure in the manifold 61 and closes switch 71 while gas flows also to the respective burner. Circuit 39 is energized, heating coils 21 which ignite the flames 43, switches 23 being initially closed. The flames heat the links 25 to open switches 23, whereupon the lamp 41 lights and remains lighted as long as all pilot flames 43 are burning. Under these conditions, the voltage on coils 31 is reduced to a point where they cease to glow.

It will be seen that the first valve 53 to be operated causes lighting of all of the pilot flames 43, i. e., the range is prepared for use or on duty, and then when any other valve 53 is operated, its burner will ignite. If any pilot mechanism becomes defective or the pilot flame goes out while the range is on duty, the respective switch 23 will close, thus causing lamp 41 to be shunted out of the circuit and go out, signalling to the operator that something is wrong with the range, requiring a correction.

If the line 33 goes dead, then the operator may open by-pass valve 67 to supply pressure to the manifold 61, sending gas to the lines 19 whereupon the flame 43 may be ignited with a match for temporary operation until power is restored in line 33. When the latter occurs the valve 67 is again closed.

When all valves 53 are turned 011, the pilot manifold bleeds oil? its pressure through throttles 20 and switch 71 opens, thereby opening circuit 39. The range is then oil duty. The lamp 41 then goes out.

The primary difference between the Fig. 2 and Fig. l circuits is that in the former the operation of any one valve 53 to open position (instead of closing of switch 35 in Fig. l) prepares the range for operation at any burner by igniting all pilot flames 43. These flames remain burning as long as any one or more valves 53 is open. However, when all valves 53 are turned off, as when a days cooking is over, all of the pilot flames go out. However, in both forms of the invention all pilot flames go out when the range is off duty.

It will be understood that while the preferred form of the invention is one in which the coils 21 of a group of igniters 17 are connected in series, it would be possible to use a system wherein there is only one burner and igniter, as for example, one in which only one of the burners of Fig. 1 is used; or only the right-hand pair of burners in Fig. 2. It follows, of course, that such individual-igniter systems might be multiplied on a single range. This would, in the case of Fig. 2, require a plurality of pressure switches 63 and in both Figs. 1 and 2 a larger transformer. While such arrangement is not preferable, it partakes of certain advantages of the invention.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in the above construction Without departing from. the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. A gas range electric igniter system comprising means adapted to supply gas under pressure, a main burner, a pilot burner located to ignite the main burner, means adapted to connect the pilot burner with the gas supply means, said pilot burner being adapted to produce a pilot flame, a pilot flame igniter coil, a normally closed thermal switch adapted in response to heat of the pilot flame to open, a voltage-operated pilot signal device, said signal device and thermal switch being connected in parallel, and circuit means connecting said igniter coil in series with the parallel-connected signal device and thermal switch.

2. Apparatus made according to claim 1 including an additional switch in said circuit means adapted when open to deenergize the coil and the signal device.

3. Apparatus made according to claim 2 including means biasing said additional switch to a normally open position, and means responsive to pressure obtained from said gas supply means adapted for closing said additional switch.

4. Apparatus made according to claim 3, including a control valve arranged to effect coordinated flow of gas from the gas supply means to said pressure-operated switch and to one of the burners.

5. Apparatus made according to claim 4, wherein there is an additional connection between said gas supply means and said pressure-responsive means, said additional connection including a manually operative valve.

6. Apparatus made according to claim 1, wherein the gas supply means includes a normally closed solenoid valve, an operating coil for said solenoid valve which when energized opens the valve, a second circuit means connected to said operating coil of the solenoid valve, and a master switch connecting a supply circuit with both of said circuit means to energize them when the switch is closed.

7. A gas range electric igniter system comprising a plurality of burners, a gas supply line, a plurality of igniters, each igniter consisting of a pilot gas line having outlet means adapted to produce a pilot flame and connected with the supply line, an ignition coil, a normally closed thermal switch responsive to heating by said pilot flame to open, a voltage-operated pilot signal device a circuit connecting said thermal switches in parallel with the pilot signal device and connecting said ignition coils in series with one another and in series with the parallel connected thermal switches and pilot signal device.

8. Apparatus made according to claim 7, including a solenoid valve in the gas supply line, a coil in said valve adapted when energized to open it, a second circuit for said solenoid coil, and a master switch adapted when closed to energize both of said circuits.

9. A gas range igniter system comprising a plurality of burners, a gas supply line, a pilot gas manifold, a plurality of igniters each consisting of a pilot connection with the pilot manifold, said connection including an outlet means adapted to produce a pilot flame, an igniter coil, and a normally closed switch adapted to open in response to heat from said pilot flame, a normally open pressure switch responsive to pressure in said manifold to close, control valves each arranged coordinately to control flow of gas from the supply line to the manifold and to a burner, a voltage-operated pilot signal device, and a circuit connecting in series said pressure switch, coils and the signal device, said igniter switches being connected in parallel with one another and with the signal device.

10. Apparatus made according to claim 9, wherein said supply line and said manifold have an interconnection independent of the connections between said valves and the manifold, said last-named connection including a manual control means.

11. Apparatus made according to claim 10, wherein a transformer is carried on the range for energizing said circuit and wherein said signal lamp is carried on the range.

12. A gas range electric igniter system comprising a main gas supply line, an electric supply line, a plurality of pilot flame igniters, each igniter including a gas connection with said gas supply line and having outlet means adapted to produce a pilot flame, an igniter coil in each igniter and a normally closed thermal switch in each igniter adapted to open in response to heat of the pilot flame, a voltage-operated pilot signal device, said signal device and thermal switches being connected in parallel, a circuit connecting said igniter coils in series with one another and with the parallel-connected signal device and switches, a normally closed solenoid valve in the gas supply line having a solenoid coil which when energized opens the valve, a second circuit connected to said solenoid coil, a transformer, and a master switch adapted when closed to connect the electric supply line with the transformer and with said solenoid coil.

13. A gas range electric igniter system comprising several burners, an igniter for each burner including an ignition coil and a gas outlet for producing a pilot flame near the coil, means adapted to prepare each burner for normal duty including an element adapted upon operation to supply ignition current to the igniter coils and gas to said pilot flame outlets, normally closed thermal switches, each responsive to the heat of one pilot flame to open, a voltage-operated pilot signal device, said signal device and thermal switches being connected in parallel, and circuit means connecting said igniter coils in series with one another and in series with the parallel-connected signal device and thermal switches.

References Cited in the file of this patent UNITED STATES PATENTS 1,535,240 Morris Apr. 28, 1925 1,646,503 Steward Oct. 25, 1927 1,734,257 Kraft NOV. 5, 1929 1,977,854 Knopp Oct. 23, 1934 2,381,591 Heymann Aug. 7, 1945 2,398,215 Eskin Apr. 9, 1946 2,558,427 Fagan June 26, 1951